Panorama da qualidade biológica da água destinada ao tratamento dialítico em pacientes sob cuidados críticos em Unidades de Terapia Intensiva / Overview of the biological quality of water intended for dialysis treatment in patients under critical care in Intensive Care Units

A incidência da lesão renal aguda caracteriza-se como evento frequente em pacientes críticos internados em Unidades de Terapia Intensiva e está associada ao aumento de mortalidade, causando grande impacto à Saúde Pública. As intercorrências clínicas são minimizadas com intervenções dialíticas, acarretando a exposição do paciente a volumes expressivos de água tratada durante a terapia renal em leito. As análises microbiológicas e de determinação de endotoxinas bacterianas em amostras de água tratada e em soluções de dialisato foram executadas em dois hospitais públicos do município de São Paulo, seguindo metodologias analíticas preconizadas em compêndios oficiais. A avaliação demonstrou que a porcentagem de resultados satisfatórios no período de 2010 a 2022 variou entre 35,2 a 100% e de 40 a 100% para as unidades hospitalares I e II para a água tratada, respectivamente; e, 100% para as soluções de dialisato para a unidade hospitalar I. A eficácia de ações delineadas pelas equipes técnicas das unidades hospitalares, na adequação da água destinada à terapia dialítica, aponta para a importância em estimular outras instituições hospitalares na padronização e implantação de melhoria contínua de seus sistemas de tratamento de água para uso em procedimento dialítico, prevenindo riscos adicionais aos pacientes expostos à terapia renal.

The incidence of acute kidney is high among critically ill patients admitted to Intensive Care Units and is associated with increased mortality, having a major impact on public health. Clinical complications are minimized with dialysis interventions, which expose patients to significant volumes of treated water during in-bed renal therapy. Microbiological analyzes and determination of bacterial endotoxins were performed on treated water samples and dialysate solutions in two public hospitals in São Paulo city, using analytical methodologies recommended in official compendia. The evaluation showed that the percentage of satisfactory results for treated water ranged from 35.2% to 100% in Hospital Unit I and from 40% to 100% in Hospital Unit II between 2010 and 2022. For dialysate solutions in Hospital Unit I, the percentage of satisfactory results was 100% during the same period. The effectiveness of actions implemented by the technical hospital teams, in adapting water for dialysis therapy, points to the importance of encouraging other hospital institutions to standardize and implement a program of continuous improvement for their water treatment systems used in dialysis procedures. This will help to prevent additional risks to patients exposed to renal therapy.

Physico-chemical and Microbiological Qualities of Abattoir Wastewater in Egbu, Imo State, Nigeria

Abbattoir waste water is of a complex composition. When discharged without being treated, poses a threat to human health and the environment. This is the practice common in Nigeria, and is worrisome.Objective: The aim of this study was to assess the physico-chemical and microbiological qualities of waste water from Egbu abattoir discharged into ‘Otamiri’ river in Owerri North local government area, Imo State, Nigeria.Methods: The microbial quality of abattoir wastewater was studied. The duration of the study was three months, from June to September, 2019. Sample collection was done in the morning (8-10am) and in the evening (4-6pm). A total of thirty samples (30) were collected from two sampling points, at the place of generation of the wastewater (Effluent source) and at the point of discharge into the river (POE). Standard methods were employed to assess the microbiological and physiochemical quality of the effluent. The microorganisms isolated from the samples included Escherichia coli, Salmonella, Staphylococcus, Aspergillus, Mucor, Listeria, Micrococcus and Candida species. The Total Heterotrophic Count (THC) of effluent samples, at source and POE were 8.51log10 cfu/ml and 6.15log10cfu/ml respectively, Total Coliform Count (TCC) for same samples were 6.77log10 cfu/ml and 4.56log10 cfu/ml respectively. The Total Fungal Count (TFC) of the effluent samples at source and at POE was 5.19log10 cfu/ml and 4.18log10 cfu/ml respectively. Results further revealed that the pH of the effluent at source was 6.58 while that at Point of Entry into the river was 7.30. The temperature of both samples was 25oC. The Total Dissolved Solid values of the effluent collected at source was higher, having a value of 1400mg/L against 1000mg/L at Point of Entry. Also the Biochemical Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) values of the effluent at source were 5.10mg/L and 8.58mg/L respectively, while the BOD and COD of the water at the POE were 4.3mg/L and 7.9mg/L respectively.Conclusion: Abattoir wastes are becoming a major environmental health challenge and being discharged into the Otamiri River indiscriminately is of public health concern. The potential public health implications associated with discharging untreated abattoir wastewater into the environment and thus, the need for adequate treatment to ensure decontamination as well as providing wastewater treatment facility is imperative.

Calidad microbiológica del agua para hemodiálisis

RESUMEN Introducción: El elevado costo del tratamiento sustitutivo de la enfermedad renal crónica representa un reto para los sistemas de salud y la exigencia de la calidad del agua de la hemodiálisis aumenta con el transcurso de la historia de la hemodiálisis. Objetivo: identificar los indicadores microbiológicos del agua para hemodiálisis ambulatoria. Métodos: Estudio descriptivo de resultados microbiológicos de 150 muestras de agua de la planta de hemodiálisis ambulatoria del Instituto de Nefrología "Dr. Abelardo Buch López" en el periodo de enero de 2019 a abril de 2020. Las muestras se analizaron en el laboratorio de microbiología de agua del Instituto de Higiene, Epidemiología y Microbiología, La Habana, mediante métodos descritos en el texto. Se utilizó estadística descriptiva. Resultados: De las muestras de agua analizadas 92 % (n=138) fueron microbiológicamente satisfactorias, 8 % (n=12) que no cumplieron los requisitos se registraron en los primeros seis meses del año 2019. En la totalidad de los informes de positividad o alerta, se procedió a la limpieza y desinfección del sistema de tratamiento. No se comprobó presencia de Pseudomonas aeruginosa en las muestras. No hubo incidencia de infecciones asociadas con el tratamiento de hemodiálisis. La determinación de endotoxinas no se realizó en el período. Conclusiones: La mayoría de los informes microbiológicos recibidos en el período de estudio cumplieron las normas establecidas. La vigilancia de la calidad del agua para hemodiálisis permite la ejecución de acciones preventivas, lo cual es determinante en el proceso de diálisis y para la calidad de vida de los pacientes.

ABSTRACT Introduction: The high cost of replacement therapy for chronic kidney disease poses a challenge to the health systems, and a better quality of the water for hemodialysis is required over time. Objective: To identify the microbiological indicators of the water for outpatient hemodialysis Methods: A descriptive study based on the microbiological results of 150 samples of water from the outpatient hemodialysis water station at the Institute of Nephrology "Dr. Abelardo Buch López", from January 2019 to April 2020. Samples were analyzed in the water microbiology laboratory at the Institute of Hygiene, Epidemiology and Microbiology, Havana by methods described in the text. Descriptive statistics was used. Results: Of the water simples analyzed, 92% (n=138) were microbiologically satisfactory, 8% (n=12) did not meet the requirements and were registered in the first half of 2019. In the event of a positivity or alert report, the treatment system was all cleaned and disinfected in each case. Pseudomonas aeruginosa was not identified in the samples. No infection was associated with the hemodialysis treatment. Endotoxin determination was not performed in this period. Conclusions: Most of the microbiological reports received during the study period met the established standards. Monitoring the quality of water for hemodialysis allows the implementation of preventive measures that are critical for the dialysis process and the quality of life of the patients.

Effects of directional adaptation on selenium tolerance and accumulation of heterotrophic Chlorella pyrenoidosa / 生物工程学报

Selenium (Se) is an essential trace element for organisms. Se deficiency will cause diseases such as Keshan disease and Kashin-Beck in human being, and huge loss to animal husbandry. Currently available Se supplements have such problems as low Se content, poor bioavailability, and poor safety. Chlorella pyrenoidosa can produce bioavailable and safe organic Se under suitable conditions, which is thus a promising Se supplement. Therefore, in this study, we tried to improve the Se tolerance and accumulation of C. pyrenoidosa by directional adaptation. To be specific, we gradually increased the concentration of Na2SeO3 in medium to domesticate C. pyrenoidosa and optimized the adapting time and concentration gradient of Na2SeO3 during the adaptation. The results showed that the adapted C. pyrenoidosa was more tolerant to Se and had stronger Se enrichment ability. In 5 L fermenter, the adapted strains could tolerate 40 mg/L Na2SeO3 and the synthesis rate of organic Se was 175.6% higher. Then, Se addition method in the 5 L fermenter was optimized. The result demonstrated that addition of Na2SeO3 at 40 mg/L during heterotrophic culture achieved the final dry weight of C. pyrenoidosa cells at 106.4 g/L, content of organic Se at 1 227 mg/kg, and synthesis rate of organic Se at 1.36 mg/(L·h). Compared with the reported highest cell density of 75 g/L and the highest organic Se content of 560 mg/kg, the corresponding figures in this study were 41.9% and 119.1% higher, respectively. In conclusion, directional adaptation can remarkably improve the Se tolerance and enrichment of C. pyrenoidosa.

Mechanism of trehalose-enhanced metabolism of heterotrophic nitrification-aerobic denitrification community under high-salt stress / 生物工程学报

Heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria are aerobic microorganisms that can remove nitrogen under high-salt conditions, but their performance in practical applications are not satisfactory. As a compatible solute, trehalose helps microorganisms to cope with high salt stress by participating in the regulation of cellular osmotic pressure, and plays an important role in promoting the nitrogen removal efficiency of microbial populations in the high-salt environment. We investigated the mechanism of exogenous-trehalose-enhanced metabolism of HN-AD community under high-salt stress by starting up a membrane aerobic biofilm reactor (MABR) to enrich HN-AD bacteria, and designed a C150 experimental group with 150 μmol/L trehalose addition and a C0 control group without trehalose. The reactor performance and the community structure showed that NH4+-N, total nitrogen (TN) and chemical oxygen demand (COD) removal efficiency were increased by 29.7%, 28.0% and 29.1%, respectively. The total relative abundance of salt-tolerant HN-AD bacteria (with Acinetobacter and Pseudofulvimonas as the dominant genus) in the C150 group reached 66.8%, an 18.2% increase compared with that of the C0 group. This demonstrated that trehalose addition promoted the enrichment of salt-tolerant HN-AD bacteria in the high-salt environment to enhance the nitrogen removal performance of the system. In-depth metabolomics analysis showed that the exogenous trehalose was utilized by microorganisms to improve proline synthesis to increase resistance to high-salt stress. By regulating the activity of cell proliferation signaling pathways (cGMP-PKG, PI3K-Akt), phospholipid metabolism pathway and aminoacyl-tRNA synthesis pathway, the abundances of phosphoethanolamine, which was one of the glycerophospholipid metabolites, and purine and pyrimidine were up-regulated to stimulate bacterial aggregation and cell proliferation to promote the growth of HN-AD bacteria in the high-salt environment. Meanwhile, the addition of trehalose accelerated the tricarboxylic acid (TCA) cycle, which might provide more electron donors and energy to the carbon and nitrogen metabolisms of HN-AD bacteria and promote the nitrogen removal performance of the system. These results may facilitate using HN-AD bacteria in the treatment of high-salt and high-nitrogen wastewater.

Advances in denitrification microorganisms and processes / 生物工程学报

Denitrification is an indispensable part of most sewage treatment systems. The biological denitrification process has attracted much attention in the past decades due to the advantages such as cost-effectiveness, process simplicity, and absence of secondary pollution. This review summarized the advances on biological denitrification processes in recent years according to the different physiological characteristics and denitrification mechanisms of denitrification microorganisms. The pros and cons of different biological denitrification processes developed based on nitrifying bacteria, denitrifying bacteria, and anaerobic ammonia-oxidizing bacteria were compared with the aim to identify the best strategy for denitrification in a complex wastewater environment. The rapid development of synthetic biology provides possibilities to develop highly-efficient denitrifying strains based on mechanistic understandings. Combined with the applications of automatic simulation to obtain the optimal denitrification conditions, cost-effective and highly-efficient denitrification processed can be envisioned in the foreseeable future.

The Optimum Duration of Flushing Dental Unit Waterlines for Microbial Removal

ABSTRACT@#This study aims to evaluate the optimum duration of flushing dental unit waterlines (DUWLs) in Universiti Sains Islam Malaysia (USIM) dental polyclinics for removal of heterotrophic bacteria. Water samples were obtained from triple air syringes at each dental chair from oral surgery clinic, outpatient clinic and polyclinic 17 at Faculty of Dentistry, USIM after 16 and 64 hours of not operating the dental units as baseline samples. This is followed by sampling after continuous flushing at 30 seconds, 1 minute, 2 minutes and 3 minutes of flushing duration. The levels of heterotrophic plate count (HPC) for each flushing duration were determined by quantification of colony forming units (CFUs) after cultivation of samples on plate count agar (PCA), R2A agar and 5% sheep blood agar (SBA). Statistically, there was no significant reduction in CFUs of HPC for all flushing duration compared to baseline (P > 0.05) with the most notable HPC reducing level after 1 minute and 3 minutes of flushing DUWLs. However, HPC level at USIM dental clinics is still exceeding the recommendation by Centers for Disease Control and Prevention (CDC) which should be less than 500 CFU/mL. The existing method of controlling DUWLs contamination in USIM dental clinics is only by flushing DUWLs 1 minute every morning prior to dental treatment as recommended by Malaysian Dental Council (MDC) without the use of chemical germicides. Thus, the flushing method alone is not reliable to reduce the number of microorganisms in the DUWLs.

Heterotrophic flagellates (Amorpha and Diaphoretiches) in phytotelmata bromeliad (Bromeliaceae) / Flagelados heterotróficos (Amorpha e Diaphoretiches) em fitotelmata de bromélia (Bromeliaceae)

Abstract Many plants may accumulate rainwater, forming phytotelmata, aquatic microhabitats inhabited by various organisms. The aim of this study was to conduct an inventory of heterotrophic flagellates associated with phytotelmata of the bromeliad Aechmea distichantha Lem., found in rocky cliffs on the Upper Paraná River. The bromeliads were removed manually from the rocky wall, the water was removed and cultures of organisms of each plant were mounted in Petri dishes. Sixteen species of heterotrophic flagellate were recorded, drawn and described, among them one species belonging to the Amorpha Domain and 15 species to the Diaphoretiches Domain. The groups with most species were Euglenida and Kinetoplastea. The low diversity of heterotrophic flagellates recorded in this study, compared to the plankton of lakes and reservoirs, is probably related to the fact that phytotelmata are habitats with extreme environmental conditions, thus selecting organisms tolerant to these environments.

Resumo Em sua superfície externa, muitas plantas podem acumular água da chuva formando fitotelmata, ou seja, micro-habitat aquáticos colonizados por diversos organismos, entre eles, os flagelados protistas. Fez-se um inventário de flagelados heterotróficos associados ao fitotelmata da bromélia Aechmea distichantha Lem., encontrada em paredões rochosos em um trecho da bacia do alto rio Paraná. As bromélias foram retiradas manualmente de paredão rochoso e, em laboratório, a água foi retirada dos tanques de cada planta, e foram montadas culturas dos organismos em placas de Petri. Os flagelados heterotróficos foram, então, observados in vivo sob microscópio óptico Olympus BX51, com sistema de contraste de interferência diferencial (DIC) acoplado. Dezesseis espécies flagelados heterotróficos foram registradas, desenhadas e descritas, sendo uma espécie pertencente ao Domínio Amorpha e 15 espécies ao Domínio Diaphoretiches. Os grupos mais especiosos foram Euglenida e Kinetoplastea. A diversidade relativamente reduzida de flagelados heterotróficos, quando comparada ao plâncton de lagos e reservatórios, pode estar relacionada ao fato de os fitotelmata serem habitats limitados, com condições ambientais extremas, selecionando, assim, organismos tolerantes a esses ambientes.

Characterization of a novel heterotrophic nitrifying and aerobically denitrifying bacterium, Halomonas sp. Z8, as a potential bioagent for wastewater treatment

Aim: The aim of the present study was to identify and characterize the functions of key microbes mediating nitrification.Methodology: After sampling the biofilm from a submerged biofilter in a marine aquaculture system, selective media were used to isolate microbial strains involved in nitrification. Isolates were identified using physiological and biochemical assays and sequencing of 16S rRNA gene. Nitrogen removal under different conditions was characterized. Nitrogen removal pathway was characterized by a 15N tracer experiment. Representation of key microbes in the biolfim was characterized by metagenomics analysis. Results: Single-factor tests showed that Halomonas sp. strain Z8 exhibited good heterotrophic nitrification and aerobic denitrification abilities, with maximum NH4+-N, NO2--N and No3--N removal rates of 2.37, 1.28 and 1.7 mg N l-1 hr-1, respectively. The 15N isotope tracer experiment confirmed the aerobic nitrogen removal pathway of strain Z8. Average NO3-removal efficiencies were all above 80% in an aerated moving bed bioreactor inoculated with strain Z8 and employed to treat synthetic marine aquaculture wastewater. Metagenomic microbial community analysis revealed that Halomonas sp. Z8 was one of the dominant taxa at genus level, suggesting a vital role in removing nitrate from bioreactor

Heterotrophic Ossification after Aggressive Rehabilitation in Patients with Trauma: A Case Report

Heterotrophic ossification (HO) is a reactive disease presenting the formation of mature lamellar bone in soft tissues. It is known to occur following surgery, soft tissue injury, or central nervous system anomalies. However, a definite cause has not yet been clearly addressed. During the process of approach, reduction, and fixation while conducting surgeries, partial injury of soft tissue is inevitable. Additionally, secondary injuries may be caused during the active and passive range of motion exercises that should be done for the recovery of joint motion after surgery. The authors experienced cases of HO that may occur during surgery and rehabilitation after surgery. The authors recognized that special care is required for patients complaining of severe pain during the early stage of rehabilitation immediately after surgery. This study aimed to reaffirm the principles of fracture treatment by reviewing the cases and to investigate the occurrence of HO after fracture surgery.

Advances in microbial degradation of chlorinated hydrocarbons / 生物工程学报

Chlorinated hydrocarbons (CAHs) threaten human health and the ecological environment due to their strong carcinogenic, teratogenic, mutagenic and heritable properties. Heterotrophic assimilation degradation can completely and effectively degrade CAHs, without secondary pollution. However, it is crucial to comprehensively understand the heterotrophic assimilation process of CAHs for its application. Therefore, we review here the characteristics and advantages of heterotrophic assimilation degradation of CAHs. Moreover, we systematically summarize current research status of heterotrophic assimilation of CAHs. Furthermore, we analyze bacterial genera and metabolism, key enzymes and characteristic genes involved in the metabolic process. Finally, we indicate existing problems of heterotrophic assimilation research and future research needs.

Avaliação da qualidade microbiológica da água em bebedourosde uma instituição de ensino superior de Caxias do Sul - RS / Microbiological quality evaluation of drinking water fountains in a higher education institution of Caxias do Sul - RS

Objetivo: Avaliar a qualidade microbiológica da água de bebedouros destinada ao consumo humano de uma instituição de ensino superior em Caxias do Sul-RS. Métodos: O método utilizado para bactérias heterotróficas foi o spread plate, e, para coliformes totais, Escherichia coli e Pseudomonas aeruginosa sendo que o método é a ausência ou presença com substrato enzimático. Foram coletadas oito amostras, cada uma com aproximadamente 150 mL de água em frascos esterilizados após desinfecção dos bicos dos bebedouros com álcool 70%. Resultados: Na primeira coleta, o bebedouro 4 foi o único que apresentou alterações, com presença de 4,5 x 101 de bactérias heterotróficas, no entanto, este nível estava de acordo com a quantidade permitida. Na segunda coleta, todas as amostras apresentaram positividade para bactérias heterotróficas, porém a amostra de número 3 estava no limite aceito pela legislação, e as demais mostraram resultados superiores a 500 UFC/mL. Todas as amostras foram negativas para as análises de Pseudomonas aeruginosa, coliformes totais e Escherichia coli. Conclusão: Apesar de os resultados terem sido negativos para Pseudomonas aeruginosa, coliformes totais e Escherichia coli, três amostras apresentaram valores superiores ao aceito pela portaria para bactérias heterotróficas, expondo números superiores a 500 UFC/mL. Conclui-se que esta água é considerada inadequada para consumo humano, baseando-se nos padrões de potabilidade estabelecidos pela portaria vigente.

Objective: To evaluate the microbiological quality of drinking water from drinking fountains intended for human consumption at a higher education institution in Caxias do Sul-RS. Methods: The method used for heterotrophic bacteria was spread plate and for total coliforms, Escherichia coli and Pseudomonas aeruginosa the method is absence or presence with enzyme-substrate. Eight samples were collected, each with approximately 150mL of water in sterilized bottles, after disinfection of the drinking nozzles with 70%. Results: In the first collection, the drinker 4 was the only one that presented alterations, with a presence of 4,5 x 10¹ of heterotrophic bacteria, however this level was in agreement with the quantity allowed. In the second sample, all samples were positive for heterotrophic bacteria, but the number 3 sample was within the limit accepted by the legislation, the others showed results higher than 500 CFU/mL. All Samples were negative for the analyzes of Pseudomonas aeruginosa, total coliforms and Escherichia coli. Conclusion: Although the results were negative for Pseudomonas aeruginosa, total coliforms and for Escherichia coli, three samples presented higher values than those accepted by Ministry of Health Ordinance 2914/2011 for heterotrophic bacteria. It is concluded that this water is considered inadequate for human consumption, based on the potability standards established by the aforementioned ordinance

Utilização de método microbiológico rápido para a enumeração de bactérias heterotróficas em água tratada para diálise: técnica de detecção microbiana pelo uso de fluorescência / Use of a rapid microbiological method for the enumeration of heterotrophic bacteria in treated water for dialysis: microbial detection technique by fluorescence

O monitoramento da qualidade da água de diálise caracteriza uma importante ferramenta para a tomada de decisões quando resultados laboratoriais insatisfatórios são disponibilizados em curto período de tempo. Os inconvenientes relacionados ao tempo de espera para a obtenção dos resultados têm conduzido à busca de métodos microbiológicos alternativos que permitam obter dados exatos, precisos e em menor tempo do que os obtidos por métodos clássicos. Este projeto teve por finalidade avaliar o desempenho do método microbiológico alternativo para a contagem de bactérias heterotróficas em água tratada para diálise através da técnica de detecção microbiana pelo uso de fluorescência. Inicialmente foi realizada a determinação do tempo mínimo de incubação para obtenção de valores de contagem confiáveis pelo método alternativo, seguido pela avaliação de desempenho do método contemplando todos os parâmetros estabelecidos em compêndios nacionais e internacionais e a demonstração da equivalência do método alternativo frente ao método tradicional, através da avaliação de 23 amostras de água tratada para diálise. Os resultados demonstraram que o método alternativo permite a quantificação de bactérias heterotróficas após 40 horas de incubação, com exatidão e precisão para o range de 5 a 100 UFC/placa, resultando em uma redução de aproximadamente 67% do tempo atualmente empregado no método tradicional. Portanto, a técnica de detecção microbiana pelo uso de fluorescência se mostrou uma opção viável para a implementação de um método microbiológico rápido para a contagem de bactérias heterotróficas em amostras de água tratada para hemodiálise

Monitoring the quality of dialysis water is an important tool for decision-making when unsatisfactory results are available in a short period of time. The drawbacks related to waiting time for obtaining results have led to the search for alternative microbiological methods that allow accurate data to be obtained in less time than those obtained by classical methods. This project aimed to evaluate the alternative microbiological method performance for the heterotrophic bacteria counts in dialysis treated water through the microbial detection technique using fluorescence. Initially, the determination of the minimum incubation time to obtain reliable count values by the alternative method was performed, followed by the performance evaluation of the method, considering all the parameters established in national and international compendiums and demonstrating the equivalence of the alternative method to the traditional method, through the evaluation of 23 samples of dialysis treated water. The results demonstrated that the alternative method allows quantification of heterotrophic bacteria after 40 hours of incubation, with accuracy and precision for the range of 5 to 100 CFU/plate, resulting in a reduction of approximately 67% of the time currently used in the traditional method. Therefore, the microbial detection technique using fluorescence showed a viable option for the implementation of a rapid microbiological method for the heterotrophic bacteria counts in samples of treated water for hemodialysis

Assessment of the nitrification process in a culture of pacific white shrimp, using artificial substrate and bacterial inoculum in a biofloc technology system (BFT) / Avaliação do processo de nitrificação no cultivo do camarão branco do pacífico Litopenaeus vannamei com uso de substrato artificial e inóculo de bactérias em sistema de bioflocos (BFT)

ABSTRACT: Litopenaeus vannamei is the most cultured marine shrimp in all types of systems including the Bioflocs Technology System (BFT). Bioflocs are formed by microorganisms, among these, autotrophic bacteria are responsible for the nitrification process. This study aimed to identify and promote the development of nitrifying bacteria by adding artificial substrates and biofloc inoculum in L. vannamei culture in a BFT system. The experiment consisted of four treatments with three replics (4x3) as follows: (1) Control: clear water in which bioflocs were formed; (2) IN (10%): clear water with biofloc inoculum (10%); (3) IB: clear water with substrate (immature "bioballs"); and (4) MB: clear water with mature "bioballs" inoculum from a recirculation system. Treatments were stocked with shrimp juveniles (4.92±0.45 g) in 12 tanks with 200 L working volume at a stocking density of 200 shrimp/m³. Shrimps were fed twice a day with a commercial feed (38% CP) following a feeding table, and daily observations intake were made over the four weeks of the experiment. Biofloc and "bioballs" samples were collected to detect the growth of the population of nitrifying and heterotrophic bacteria by FISH. There was no significant difference between treatments (P>0.05) for survival, obtaining mean values greater than 88%. The IN (10%) treatment had lower concentrations of ammonia and nitrite, and nitrate concentration increased, while MB had a higher weight and biomass final, productivity, weekly weight gain and lower conversion of apparent feed for production performance results.

RESUMO: Litopenaeus vannamei é o camarão marinho mais cultivado em todos os tipos de sistemas, incluindo o Sistema de Tecnologia de Bioflocos (BFT). Os bioflocos são formados por microorganismos, entre estes, bactérias autotróficas que são responsáveis pelo processo de nitrificação. Este estudo teve como objetivo identificar e promover o desenvolvimento de bactérias nitrificantes pela adição de substratos artificiais e inóculo de bioflocos no cultivo de L. vannamei em sistema BFT. O experimento consistiu de quatro tratamentos com três repetições (4x3), sendo: (1) Controle: água limpa, na qual foram formados os bioflocos; (2) IN (10%): água limpa com inóculo de bioflocos (10%); (3) BI: água limpa com substrato ("bioballs" imaturos); e (4) BM: água limpa com inóculo de "bioballs" maduros de um sistema de recirculação. Para tanto, os tratamentos foram estocados com juvenis de camarão (4,92±0,45 g) em 12 tanques com 200 L de volume útil com densidade de 200 camarões/m³. Os camarões foram alimentados duas vezes ao dia com ração comercial (38% PB) seguindo uma tabela de alimentação, e observações diárias foram feitas ao longo das quatro semanas de experimento. Amostras de bioflocos e "bioballs" foram coletadas para detectar o crescimento da população de bactérias nitrificantes e heterotróficas por FISH. Não houve diferença significativa entre os tratamentos (P>0,05) para sobrevivência, obtendo-se valores médios superiores a 88%. O tratamento com IN (10%) apresentou menores concentrações de amônia e nitrito, e a concentração de nitrato aumentou, enquanto o BM apresentou maior peso e biomassa final, produtividade, ganho de peso semanal e menor conversão alimentar aparente para resultados de desempenho zootécnico.

Mid-term effectiveness of arthrolysis and hinged external fixation for treatment of stiff elbow caused by heterotrophic ossification / 中国修复重建外科杂志

Objective: To evaluate the mid-term effectiveness of arthrolysis and hinged external fixation for the treatment of stiff elbow caused by heterotrophic ossification. Methods: Between January 2014 and December 2017, 11 patients with stiff elbow caused by heterotrophic ossification were admitted. There were 9 males and 2 females with an average age of 32 years (range, 14-48 years), and left side in 6 cases and right side in 5 cases. The cause of stiff elbow included humerus fracture in 5 cases, ulna fracture in 2 cases, fracture of capitulum radii in 1 case, dislocation of capitulum radii in 1 case, terrible triad of the elbow in 1 case, and soft tissue injury in 1 case. The disease duration ranged from 7 to 18 months (mean, 11 months). Preoperative active range of motion of elbow was (19.6±17.5)° and Mayo score was 34.1±9.7. All patients received the treatment of arthrolysis and debridement of heterotrophic ossification lesion combining hinged external fixator, and active and passive rehabilitation with the help of hinged external fixator. The hinged external fixators were removed after 2 months. Results: All patients were followed up 13-36 months (mean, 19.1 months). All incisions healed by first intention, and no complication of infection or nerve lesion occurred postoperatively. At last follow-up, the results of X-ray films showed that no heterotrophic ossification recurred. The active range of motion of elbow was (116.4±16.6)° and Mayo score was 93.2±7.8, showing significant differences when compared with preoperative ones ( t=17.508, P=0.000; t=16.618, P=0.000). Conclusion: The application of arthrolysis and debridement of heterotrophic ossification lesion combining hinged external fixator can improve the elbow's range of motion significantly and obtain a good mid-term effectiveness.

Advances in heterotrophic nitrification-aerobic denitrifying bacteria for nitrogen removal under extreme conditions / 生物工程学报

Heterotrophic nitrification-aerobic denitrification (HN-AD) is an enrichment and breakthrough theory of traditional autotrophic nitrification heterotrophic denitrification. Heterotrophic nitrification-aerobic denitrifiers with the feature of wide distribution, strong adaptability and unique metabolic mechanism have many special advantages, including fast-growing, rapid biodegradability and long lasting activity, which can rapidly remove ammonia nitrogen, nitrate nitrogen (NO₃⁻-N) and nitrite nitrogen (NO₂⁻-N) under aerobic conditions simultaneously. Therefore, HN-AD bacteria show the important potential for denitrification under extreme conditions with high-salt, low-temperature or high-ammonia nitrogen environment, and HN-AD bacteria attract extensive attention in the field of biological denitrification of wastewater. In this review, we first introduce the previously reported HN-AD bacterial species which have denitrification performance in the extreme environments and state their typical metabolic mechanism. Then, we systematically analyze the nitrogen removal characteristics and potential under extreme conditions. We also briefly describe the progress in the application of HN-AD bacterial. Finally, we outlook the application prospects and research directions of HN-AD denitrification technology.

Bacterial Community Profile and Phylogenetic Diversity of Water and Surface Sediments in Iko River Estuary, Akwa Ibom State- Nigeria

A large amount of crude oil is spilled annually into the terrestrial and aquatic environments in Nigeria. This tends to upset the natural equilibrium of the marine environment as a microbial habitat. Thus, there is a need to evaluate the effect of exposure to crude oil on bacterial load and diversity using Iko River and Odoro Ikot pond as the study and pristine sites respectively. The bacterial isolates were molecularly identified using the 16S rRNA sequencing protocol. The total heterotrophic bacterial count (THBC) in the surface water (SW), sub-surface water (SSW) and sediment segments of Iko River ranged from 2.23±0.87 to 9.67 ± 0.43 x 106 CFU/ML while the THBC in the SW, SSW and sediment segments of the pristine site (Odoro Ikot pond) ranged from 1.87±0.53 to 4.8± 0.04x106 CFU/ML. The sediment had a significantly higher (P<0.05) THBC than the water segments (SW and SSW) in both Iko River and Odoro Ikot pond. The hydrocarbon utilizing bacteria (HUB) count in Odoro Ikot pond ranged from 0.40 ± 0.01 to 1.10 ± 0.03 x 106 CFU/ML while the HUB count in Iko River ranged from 0.53 ± 0.02 to 0.93 ± 0.04 x 106 CFU/ML, making Iko River have a higher number of total heterotrophic bacteria and hydrocarbon utilizing bacteria than Odoro Ikot pond. The Proteobacteria isolates had the highest bacterial diversity (77%) while members of the Firmicutes phylum had a 23% bacterial diversity. However, higher bacterial count and diversity were obtained from the sediment segment than from the water segments in both Iko River and Odoro Ikot pond implying that the sediment is more favourable for bacterial growth. Although the bacterial profile was affected by exposure to crude oil, there were variations in the phylogenetic diversities obtained from the different water segments attributable to crude oil concentration.

GRUPOS FUNCIONALES MICROBIANOS EN SUELOS CONTAMINADOS CON TOXAFENO EN EL DEPARTAMENTO DEL CESAR, COLOMBIA / MICROBIAL FUNCTIONAL GROUPS IN SOILS CONTAMINATED WITH TOXAPHENE IN THE DEPARTMENT OF CESAR, COLOMBIA

El toxafeno es un plaguicida organoclorado que se empleó por años en el cultivo de algodón. Después de su prohibición, en las antiguas bodegas de Cenalgodón (Caracolicito, Cesar) se realizaron malas prácticas de manejo que generaron la contaminación de suelos. Debido a esta problemática, y a la reconocida importancia de los grupos funcionales microbianos como indicadores de calidad, se realizó un análisis en suelos contaminados y sin contaminar para evaluar el efecto del toxafeno sobre algunas comunidades microbianas durante dos períodos climáticos. Fueron evaluadas algunas poblaciones de microorganismos cultivables relacionados con los ciclos del carbono y nitrógeno por el método de recuento directo en placa y número más probable utilizando medios de cultivos selectivos. Los recuentos totales de las poblacionales de bacterias, hongos (Log UFC/g de suelo) y grupos funcionales microbianos del C y del N (Log NMP/g de suelo) aislados del suelo contaminado con toxafeno fueron inferiores a los registrados para el suelo testigo durante el período de sequía y de lluvias (p≤ 0,05). Para ambos suelos algunos grupos de microorganismos se correlacionaron positivamente, lo que indica su participación sinérgica en el ciclado de nutrientes; esto podría favorecer a la recuperación del suelo contaminado y al mantenimiento del ecosistema, siempre y cuando se mejoren las condiciones ambientales y fisicoquímicas del sistema.

Toxaphene is an organochlorine pesticide that was used for years in the cultivation of cotton. After its prohibition in the old cellars of Cenalgodon (Caracolicito - Cesar), bad management practices were carried out that generated soil contamination. Due to this problem, and to the well-recognized importance of the functional microbial groups as quality indicators, a soil analysis was performed in contaminated and uncontaminated soils to evaluate the effect of toxaphene on some microbial communities during two climatic periods. Some populations of cultivable microorganisms related to the carbon and nitrogen cycles were evaluated by the method of direct plate count and most probable number using selective culture media. The total counts of the population of bacteria, fungi (Log CFU / g of soil) and microbial functional groups of C and N (Log NMP / g of soil) isolated from the soil contaminated with toxaphene were lower than those recorded for the control soil during the drought and rain periods (p≤0.05). Some groups of microorganisms were correlated positively for both soils indicating their synergistic participation in the cycling of nutrients, which could favor the recovery of contaminated soil and the maintenance of the ecosystem as long as the environmental and the physicochemical conditions of the system are improved.

Avaliação microbiológica de fontes de água de escolas públicas e privadas da cidade de Santa Rita (PB) / Microbiological evaluation of water fountains of public and private schools from Santa Rita city (PB), Brazil

RESUMO A quantidade e a qualidade da água potável ingerida estão diretamente relacionadas com a saúde humana. A garantia de segurança e potabilidade depende do funcionamento adequado de etapas que vão desde o tratamento até a distribuição; e, caso alguma delas apresente falhas, pode haver processo de contaminação. Partindo desse pressuposto, objetivou-se com o presente trabalho verificar a qualidade microbiológica da água fornecida em bebedouros de escolas públicas e privadas de ensino fundamental e infantil da cidade de Santa Rita, na Paraíba. As análises de coliformes totais, termotolerantes e bactérias heterotróficas foram realizadas segundo os padrões e metodologias da American Public Health Association. Por meio dos resultados deste trabalho, baseados nos padrões contidos na Portaria nº 2.914, de 12 de dezembro de 2011, do Ministério da Saúde, em relação à contagem de coliformes totais, verificou-se que 100% das amostras apresentavam-se impróprias para consumo, enquanto coliformes termotolerantes foram detectados em 33,33% das amostras). A contagem de bactérias heterotróficas variou entre 1,5x102 e 1,6x103 UFC.mL-1, sendo assim, todas as amostras foram consideradas impróprias ao consumo humano. Sugere-se um rigoroso controle de qualidade e a adoção de boas práticas, tais como tratamento da água, limpezas periódicas e manutenção dos reservatórios, filtros e bebedouros, bem como medidas preventivas e corretivas para manutenção da higiene e do controle microbiológico dos reservatórios de água, de forma a ser disponibilizada água com qualidade.

ABSTRACT The quantity and the quality of drinking water intake are directly related to human health. In order to guarantee the safety and potability of drinking water, a series of steps ranging from treatment to distribution must work properly, and if any of them fails, contamination can occur. Based on this assumption, the aim of the present work was to check the microbiological water quality in drinking fountains from pre-school and elementary public and private schools in the city of Santa Rita, Paraíba, Brazil. The analyzes of total coliforms, thermotolerant bacteria and heterotrophic bacteria were carried out according to the standards and methodologies of the American Public Health Association. Based on the standards from Decree 2,914 of December 12, 2011, from the Brazilian Health Ministry, of the total coliforms, 12 samples (100%) were unfit for consumption, and thermotolerant coliforms were detected in 33.33% of the samples. The heterotrophic bacteria count ranged from 1.5x102 to 1.6x103 CFU.mL-1, and as such, all of the samples were unsuitable for human consumption. Thus, we suggest the implementation of a rigorous maintenance process that monitors and controls hygiene and microbiological contamination in the drinking fountains at these locations. Additionally, we recommend the adoption of preventive and corrective measures such as water treatment, regular cleaning and the maintenance of reservoirs, filters and drinking fountains, in order to provide quality water at these schools.

Characterization and optimization of a heterotrophic bacterium for sulfide degradation / 生物工程学报

The emission of hydrogen sulfide in the waste gas from slaughter plant, fishmeal feed processing and some other food industrial processing could cause serious air pollution to the surrounding environment. The purpose of this study was to screen heterotrophic bacterium strains for the removal of hydrogen sulfide odor. One heterotrophic bacterial mutant ZJNB-B3 was derived from the sulfide degrader Bacillus cereus XJ-2 and its sulfide removal efficiency was 97%. Based on the morphology studies, biochemical tests and 16S rRNA gene analysis, the strain was identified as Bacillus cereus ZJNB-B3. The NCBI GenBank accession number is MF679650. Batch tests showed that the strain tolerated up to 300 mg/L of toxic S²⁻ concentration. Response surface methodology was applied to optimize the conditions of degradation of sulfide. The optimal parameters were as follows: initial sulfide concentration 211.8 mg/L, initial pH 6.72, inoculum volume 5.04%, and incubation temperature 30 ℃. The accumulated sulfate concentration was 63.8 mg/L and the sulfide removal efficiency was 97.3% after 48 h incubation. No sulfuric acid was generated during sulfide oxidation by the strain. Sulfide could be removed effectively by this strain under mild pH conditions. The results suggested that the strain may have great industrial application potential. This study provides the fundamentals for the removal of hydrogen sulfide gas.