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1.
Article in English | WPRIM | ID: wpr-1030540

ABSTRACT

Aims@#This study was aimed to characterize laccase from a selected fungal strain and examine the enzyme’s ability to remove lignin from paper pulp. @*Methodology and results@#Twelve fungal strains were screened for laccase production, resulting in the selection of Trichoderma sp. UBDFT12. The highest laccase activity (103 U/L) was observed from the culture filtrate on the fourth day of incubation. The optimum temperature and pH for the enzyme were 40 °C and pH 4, respectively. However, the enzyme stability was found to be reduced with time after 1 h incubation. At 1 mM, it was found that AgNO3, CaCO3, CuSO4, KCl, MgSO4, MnSO4 and ZnSO4 increased the laccase activity to 107, 107, 111, 112, 106, 105 and 107%, respectively, whereas FeSO4 and NH4Cl reduced the activity to 84 and 99%, respectively. The addition of 1% H2O2, 1% NaCl, 1% sodium dodecyl sulphate (SDS), 1 mM ethylenediaminetetraacetic acid (EDTA), 10 mM EDTA, 1 mM phenanthroline and 10 mM phenanthroline reduced the activity to 95, 73, 0, 79, 79, 73 and 37%, respectively. The culture filtrate was partially purified via ammonium sulphate precipitation and the recovered enzyme had a specific activity of 0.176 U/mg. Using sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of the enzyme was approximately 65 kDa and its activity was confirmed by zymography. The culture filtrate was also found to be able to remove lignin from different types of paper pulp.@*Conclusion, significance and impact of study@#Laccase produced by Trichoderma sp. UBDFT12 was found to have the ability to remove lignin from paper pulp.

2.
Article | IMSEAR | ID: sea-219462

ABSTRACT

This study evaluated the influence of organic fertilizers produced from spent lubricating oil (SLO) spiked aerobic composting technique on hydrocarbon degradation rate in soils. The compost windrows (Ft2 and Ft4), consisting of kitchen and agricultural wastes, were spiked with varying concentrations (2% and 4%) of SLO. The resultant organic fertilizers were employed as amendment in pollution simulated potted soils laid out in a complete randomized block design with three replications for 90 days. Results revealed higher counts of hydrocarbon utilizing microbes (HUB: 4.2±0.02×104cfu/g in Ft2, 3.0±0.02×104cfu/g in Ft4; HUF: 3.9±0.2×104cfu/g in Ft2, 2.5±0.02×104cfu/g in Ft4) in spiked compost compared to the control, Ft0 (HUB: 7.9±0.02×103cfu/g; HUF: 6.0±0.2×103cfu/g). Mean count in amended soils reflected a dose-dependent increase which followed the trend: Ft2 ? Ft0 ? Ft4 for the 5% (3.7×108 cfu/g), 10% (9.2×107 cfu/g) and 15% (6.9×107 cfu/g) levels of fertilizer treatments respectively. There was a significant (P<0.05) reduction in the TPH content of soils after 90days treatment with organic fertilizers. Generally, remediation efficiency followed the order: Ft2 ? Ft0 ? Ft4, with the highest (11.51%) achieved at 5% Ft2 application. Spiking technique was responsible for the higher counts of hydrocarbon utilizing microbes and enhanced bioremediation associated with the use of fertilizers Ft2.

3.
Rev. colomb. biotecnol ; 25(1)jun. 2023.
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1535723

ABSTRACT

Se evaluó la biodegradación de polietilenglicol de peso molecular 400 - PEG 400 con el consorcio Pseudomonas sp. y Rhizobium trifolii en reactores en Batch; para determinar las condiciones óptimas de operación del reactor se preparó medio con sales mínimas esenciales suplementado con peptonaCSMEP; en estos medios se estimó el comportamiento del consorcio con condiciones de temperatura entre 15-37°C, pH en un rango de 5-9 y concentración de PEG 400 del .1-2%. Con los resultados obtenidos en estos ensayos previos se ensamblaron tres reactores en Batch - BK. Se analizaron 14 muestras del contenido de cada uno de los reactores durante 20 días para medir la biodegradación del PEG 400 usando demanda química de oxígeno - DQO en sistema de digestión cerrado. Se obtuvo una disminución de hasta el 98.5% del poliéter, lo que mostró que la simbiosis fue efectiva para alcanzar una remoción importante del contaminante.


The biodegradation of polyethylene glycol of molecular weight 400 - PEG 400 was evaluated with the consortium Pseudomonas sp. and Rhizobium trifolii in Batch reactors. To determine the optimal operating conditions of the reactor, a medium with minimum essential salts supplemented with CSMEP peptone was prepared; In these media, the behavior of the consortium was estimated with temperature conditions between 15-37°C, pH in a range of 5-9 and PEG 400 concentration of .1-2%. With the results obtained in these previous tests, three Batch - BK reactors were assembled. 14 samples of the contents of each one of the reactors were analyzed during 20 days to measure the biodegradation of PEG 400 using chemical oxygen demand - COD in a closed digestion system. A decrease of up to 98.5% of the polyether was obtained, which showed that the symbiosis was effective to achieve an important removal of the contaminant.

4.
Chinese Journal of Biotechnology ; (12): 1861-1866, 2023.
Article in Chinese | WPRIM | ID: wpr-981175

ABSTRACT

Synthetic plastics have been widely used in various fields of the national economy and are the pillar industry. However, irregular production, plastic product use, and plastic waste piling have caused long-term accumulation in the environment, contributing considerably to the global solid waste stream and environmental plastic pollution, which has become a global problem to be solved. Biodegradation has recently emerged as a viable disposal method for a circular plastic economy and has become a thriving research area. In recent years, important breakthroughs have been made in the screening, isolation, and identification of plastic-degrading microorganisms/enzyme resources and their further engineering, which provide new ideas and solutions for treating microplastics in the environment and the closed-loop bio-recycling of waste plastics. On the other hand, the use of microorganisms (pure cultures or consortia) to further transform different plastic degradants into biodegradable plastics and other compounds with high added value is of great significance, promoting the development of a plastic recycling economy and reducing the carbon emission of plastics in their life cycle. We edited a Special Issue on the topic of "Biotechnology of Plastic Waste Degradation and Valorization", focusing on the researches progress in three aspects: Mining microbial and enzyme resources for plastic biodegradation, Design and engineering of plastic depolymerase, and biological high-value transformation of plastic degradants. In total, 16 papers have been collected in this issue including reviews, comments, and research articles, which provide reference and guidance for further development of plastic waste degradation and valorization biotechnology.


Subject(s)
Biodegradable Plastics , Biodegradation, Environmental , Biotechnology
5.
Chinese Journal of Biotechnology ; (12): 1867-1882, 2023.
Article in Chinese | WPRIM | ID: wpr-981176

ABSTRACT

At present, the negative impact caused by white pollution has spread to all aspects of human society economy, ecosystem, and health, which causes severe challenges for developing the circular bioeconomy. As the largest plastic production and consumption country in the world, China has shouldered an important responsibility in plastic pollution control. In this context, this paper analyzed the relevant strategies of plastic degradation and recycling in the United States, Europe, Japan and China, measured the literature and patents in this field, analyzed the status quo of technology from the perspective of research and development trends, major countries, major institutions, and discussed the opportunities and challenges faced by the development of plastic degradation and recycling in China. Finally, we put forward future development suggestions which include the integration of policy system, technology path, industry development and public cognition.


Subject(s)
Humans , Plastics , Ecosystem , Environmental Pollution , Recycling , Policy
6.
Chinese Journal of Biotechnology ; (12): 1889-1911, 2023.
Article in Chinese | WPRIM | ID: wpr-981178

ABSTRACT

The pollution caused by improper handling of plastics has become a global challenge. In addition to recycling plastics and using biodegradable plastics, an alternative solution is to seek efficient methods for degrading plastics. Among them, the methods of using biodegradable enzymes or microorganisms to treat plastics have attracted increasing attention because of its advantages of mild conditions and no secondary environmental pollution. Developing highly efficient depolymerizing microorganisms/enzymes is the core for plastics biodegradation. However, the current analysis and detection methods cannot meet the requirements for screening efficient plastics biodegraders. It is thus of great significance to develop rapid and accurate analysis methods for screening biodegraders and evaluating biodegradation efficiency. This review summarizes the recent application of various commonly used analytical techniques in plastics biodegradation, including high performance liquid chromatography, infrared spectroscopy, gel permeation chromatography, and determination of zone of clearance, with fluorescence analysis techniques highlighted. This review may facilitate standardizing the characterization and analysis of plastics biodegradation process and developing more efficient methods for screening plastics biodegraders.


Subject(s)
Biodegradable Plastics/chemistry , Biodegradation, Environmental
7.
Chinese Journal of Biotechnology ; (12): 1930-1948, 2023.
Article in Chinese | WPRIM | ID: wpr-981180

ABSTRACT

Polyolefin plastics are a group of polymers with C-C backbone that have been widely used in various areas of daily life. Due to their stable chemical properties and poor biodegradability, polyolefin plastic waste continues to accumulate worldwide, causing serious environmental pollution and ecological crises. In recent years, biological degradation of polyolefin plastics has attracted considerable attention. The abundant microbial resources in the nature offer the possibility of biodegradation of polyolefin plastic waste, and microorganisms capable of degrading polyolefin have been reported. This review summarizes the research progress on the biodegradation microbial resources and the biodegradation mechanisms of polyolefin plastics, presents the current challenges in the biodegradation of polyolefin plastics, and provides an outlook on future research directions.


Subject(s)
Plastics/metabolism , Polymers/metabolism , Polyenes , Biodegradation, Environmental
8.
Chinese Journal of Biotechnology ; (12): 1949-1962, 2023.
Article in Chinese | WPRIM | ID: wpr-981181

ABSTRACT

Polyethylene (PE) is the most abundantly used synthetic resin and one of the most resistant to degradation, and its massive accumulation in the environment has caused serious pollution. Traditional landfill, composting and incineration technologies can hardly meet the requirements of environmental protection. Biodegradation is an eco-friendly, low-cost and promising method to solve the plastic pollution problem. This review summarizes the chemical structure of PE, the species of PE degrading microorganisms, degrading enzymes and metabolic pathways. Future research is suggested to focus on the screening of high-efficiency PE degrading strains, the construction of synthetic microbial consortia, the screening and modification of degrading enzymes, so as to provide selectable pathways and theoretical references for PE biodegradation research.


Subject(s)
Polyethylene/metabolism , Bacteria/metabolism , Plastics/metabolism , Biodegradation, Environmental , Microbial Consortia
9.
Chinese Journal of Biotechnology ; (12): 1963-1975, 2023.
Article in Chinese | WPRIM | ID: wpr-981182

ABSTRACT

Polyurethane (PUR) plastics is widely used because of its unique physical and chemical properties. However, unreasonable disposal of the vast amount of used PUR plastics has caused serious environmental pollution. The efficient degradation and utilization of used PUR plastics by means of microorganisms has become one of the current research hotspots, and efficient PUR degrading microbes are the key to the biological treatment of PUR plastics. In this study, an Impranil DLN-degrading bacteria G-11 was isolated from used PUR plastic samples collected from landfill, and its PUR-degrading characteristics were studied. Strain G-11 was identified as Amycolatopsis sp. through 16S rRNA gene sequence alignment. PUR degradation experiment showed that the weight loss rate of the commercial PUR plastics upon treatment of strain G-11 was 4.67%. Scanning electron microscope (SEM) showed that the surface structure of G-11-treated PUR plastics was destroyed with an eroded morphology. Contact angle and thermogravimetry analysis (TGA) showed that the hydrophilicity of PUR plastics increased along with decreased thermal stability upon treatment by strain G-11, which were consistent with the weight loss and morphological observation. These results indicated that strain G-11 isolated from landfill has potential application in biodegradation of waste PUR plastics.


Subject(s)
Plastics/metabolism , Polyurethanes/chemistry , RNA, Ribosomal, 16S , Bacteria/genetics , Biodegradation, Environmental
10.
Chinese Journal of Biotechnology ; (12): 1976-1986, 2023.
Article in Chinese | WPRIM | ID: wpr-981183

ABSTRACT

Although polyurethane (PUR) plastics play important roles in daily life, its wastes bring serious environmental pollutions. Biological (enzymatic) degradation is considered as an environmentally friendly and low-cost method for PUR waste recycling, in which the efficient PUR-degrading strains or enzymes are crucial. In this work, a polyester PUR-degrading strain YX8-1 was isolated from the surface of PUR waste collected from a landfill. Based on colony morphology and micromorphology observation, phylogenetic analysis of 16S rDNA and gyrA gene, as well as genome sequence comparison, strain YX8-1 was identified as Bacillus altitudinis. The results of high performance liquid chromatography (HPLC) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) showed that strain YX8-1 was able to depolymerize self-synthesized polyester PUR oligomer (PBA-PU) to produce a monomeric compound 4, 4'-methylene diphenylamine. Furthermore, strain YX8-1 was able to degrade 32% of the commercialized polyester PUR sponges within 30 days. This study thus provides a strain capable of biodegradation of PUR waste, which may facilitate the mining of related degrading enzymes.


Subject(s)
Polyurethanes/chemistry , Polyesters/chemistry , Chromatography, Liquid , Phylogeny , Tandem Mass Spectrometry , Bacteria/metabolism , Biodegradation, Environmental
11.
Chinese Journal of Biotechnology ; (12): 1987-1997, 2023.
Article in Chinese | WPRIM | ID: wpr-981184

ABSTRACT

With the environmental pollution caused by waste plastics becoming increasingly serious, biodegradable polyester has become the focus of public attention. Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable polyester formed by the copolymerization of aliphatic and aromatic groups, which has excellent performance of both. The degradation of PBAT under natural conditions requires strict environmental conditions and long degradation cycle. To address these shortcomings, this study explored the application of cutinase in PBAT degradation and the impact of butylene terephthalate (BT) content on the biodegradability of PBAT, so as to improve the degradation rate of PBAT. Five Polyester degrading enzymes from different sources were selected to degrade PBAT to pick out the most efficient enzyme. Subsequently, the degradation rate of PBAT materials with different BT content were determined and compared. The results showed that cutinase ICCG was the best enzyme for PBAT biodegradation, and the higher the BT content, the lower the degradation rate of PBAT. Furthermore, the optimum temperature, buffer type, pH, the ratio of enzyme to substrate (E/S) and substrate concentration in the degradation system were determined to be 75 ℃, Tris HCl, 9.0, 0.4% and 1.0% respectively. These findings may facilitate the application of cutinase in PBAT degradation.


Subject(s)
Polyesters/chemistry , Adipates
12.
Chinese Journal of Biotechnology ; (12): 500-515, 2023.
Article in Chinese | WPRIM | ID: wpr-970388

ABSTRACT

As a widespread pollutant in the environment, research on microplastics have attracted much attention. This review systematically analyzed the interaction between microplastics and soil microorganisms based on existing literatures. Microplastics can change the structure and diversity of soil microbial communities directly or indirectly. The magnitude of these effects depends on the type, dose and shape of microplastics. Meanwhile, soil microorganisms can adapt to the changes caused by microplastics through forming surface biofilm and selecting population. This review also summarized the biodegradation mechanism of microplastics, and explored the factors affecting this process. Microorganisms will firstly colonize the surface of microplastics, and then secrete a variety of extracellular enzymes to function at specific sites, converting polymers into lower polymers or monomers. Finally, the depolymerized small molecules enter the cell for further catabolism. The factors affecting this degradation process are not only the physical and chemical properties of the microplastics, such as molecular weight, density and crystallinity, but also some biological and abiotic factors that affect the growth and metabolism of related microorganisms and the enzymatic activities. Future studies should focus on the connection with the actual environment, and develop new technologies of microplastics biodegradation to solve the problem of microplastic pollution.


Subject(s)
Microplastics , Plastics , Soil , Polymers , Biodegradation, Environmental
13.
Chinese Journal of Biotechnology ; (12): 1202-1216, 2023.
Article in Chinese | WPRIM | ID: wpr-970433

ABSTRACT

Biodegradation of pyridine pollutant by microorganisms is one of the economical and effective methods to solve the environmental pollution of pyridine under high salinity conditions. To this end, screening of microorganisms with pyridine degradation capability and high salinity tolerance is an important prerequisite. In this paper, a salt-resistant pyridine degradation bacterium was isolated from the activated sludge of Shanxi coking wastewater treatment plant, and identified as a bacterium belonging to Rhodococcus on the basis of colony morphology and 16S rDNA gene phylogenetic analysis. Salt tolerance experiment showed that strain LV4 could grow and degrade pyridine with the initial concentration of 500 mg/L completely in 0%-6% saline environment. However, when the salinity was higher than 4%, strain LV4 grew slowly and the degradation time of pyridine by strain LV4 was significantly prolonged. Scanning electron microscopy showed that the cell division of strain LV4 became slower, and more granular extracellular polymeric substance (EPS) was induced to secrete in high salinity environment. When the salinity was not higher than 4%, strain LV4 responded to the high salinity environment mainly through increasing the protein content in EPS. The optimum conditions for pyridine degradation by strain LV4 at 4% salinity were 30 ℃, pH 7.0 and 120 r/min (DO 10.30 mg/L). Under these optimal conditions, strain LV4 could completely degrade pyridine with an initial concentration of 500 mg/L at a maximum rate of (29.10±0.18) mg/(L·h) after 12 h adaptation period, and the total organic carbon (TOC) removal efficiency reached 88.36%, indicating that stain LV4 has a good mineralization effect on pyridine. By analyzing the intermediate products in pyridine degradation process, it was speculated that strain LV4 achieved pyridine ring opening and degradation mainly through two metabolic pathways: pyridine-ring hydroxylation and pyridine-ring hydrogenation. The rapid degradation of pyridine by strain LV4 in high salinity environment indicates its application potential in the pollution control of high salinity pyridine environment.


Subject(s)
Rhodococcus/genetics , Phylogeny , Extracellular Polymeric Substance Matrix/metabolism , Sewage , Biodegradation, Environmental , Pyridines/metabolism
14.
Chinese Journal of Biotechnology ; (12): 3436-3450, 2023.
Article in Chinese | WPRIM | ID: wpr-1007968

ABSTRACT

Azo dyes are widely used in textile, paper and packing industries, and have become one of the research hot spots in dye wastewater treatment because of their carcinogenicity, teratogenic mutagenicity, stable structure and degradation difficulty. In this study, the biodecolorization of acid orange 7 (AO7), an azo dye, by different white rot fungi was investigated, and the effect of different conditions on the decolorization rate of the dye was analyzed. At the same time, the degradation liquor was analyzed and the phytotoxicity experiment was performed to deduce the possible degradation pathway of AO7 and assess the toxicity of its degradation products. The results showed that the decolorization rate reached 93.46% in 24 h at pH 4.5, 28 ℃ by Pleurotus eryngii and Trametes versicolor when AO7 concentration was 100 mg/L. The biodegradation pathway of AO7 was initiated by the cleavage of the azo bond of AO7, generating p-aminobenzenesulfonic acid and 1-amino-2-naphthol. Subsequently, the sulfonic acid group of p-aminobenzene sulfonic acid was removed to generate hydroquinone. Moreover, the 1-amino-2-naphthol was de-ringed to generate phthalic acid and p-hydroxybenzaldehyde, and then further degraded into benzoic acid. Finally, hydroquinone and benzoic acid may be further oxidized into other small molecules, carbon dioxide and water. Phytotoxicity experiment showed that the toxicity of AO7 could be reduced by P. eryngii and T. versicolor.


Subject(s)
Hydroquinones , Trametes , Azo Compounds , Benzoic Acid
15.
Chinese Journal of Biotechnology ; (12): 4445-4462, 2023.
Article in Chinese | WPRIM | ID: wpr-1008035

ABSTRACT

Plastics are widely used in human daily life, which bring great convenience. Nevertheless, the disposal of a large amount of plastic wastes also brings great pressure to the environment. Polyethylene terephthalate (PET) is a polymer thermoplastic material produced from petroleum. It has become one of the most commonly used plastics in the world due to its durability, high transparency, light weight and other characteristics. PET can exist in nature for a long time due to its complex structure and the difficulty in degradation, which causes serious pollution to the global ecological environment, and threatens human health. The degradation of PET wastes has since become one of the global challenges. Compared with physical and chemical methods, biodegradation is the greenest way for treating PET wastes. This review summarizes the recent advances on PET biodegradation including microbial and enzymatic degradation of PET, biodegradation pathway, biodegradation mechanisms, and molecular modification of PET-degrading enzymes. In addition, the prospect for achieveing efficient degradation of PET, searching and improving microorganisms or enzymes that can degrade PET of high crystallinity are presented, with the aimto facilitate the development, application and molecular modification of PET biodegradation microorganisms or enzymes.


Subject(s)
Humans , Polyethylene Terephthalates/metabolism , Polymers , Biodegradation, Environmental , Petroleum
16.
Braz. j. biol ; 83: 1-8, 2023. graf
Article in English | LILACS, VETINDEX | ID: biblio-1468842

ABSTRACT

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.


Subject(s)
Aspergillus flavus/isolation & purification , Biotransformation , Keratins/analysis , Keratins/toxicity
17.
Braz. j. biol ; 832023.
Article in English | LILACS-Express | LILACS, VETINDEX | ID: biblio-1469058

ABSTRACT

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

18.
Braz. j. biol ; 83: e246389, 2023. graf
Article in English | LILACS, VETINDEX | ID: biblio-1285638

ABSTRACT

Abstract Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.


Resumo A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.


Subject(s)
Animals , Chickens , Feathers , Fermentation , Fungi , Industrial Waste , Keratins/metabolism
19.
Article | IMSEAR | ID: sea-221249

ABSTRACT

Eco-friendly polymers are biodegraded by microorganisms, making it easy to transform them into safer, more straightforward forms. These biodegradable materials can be used in a variety of industries, including medicine, agriculture, drug release research, food and medication packaging, and artificial skin grafts. It prevents environmental accumulation and cannot result in pollution of the land, air, or water

20.
Rev. colomb. biotecnol ; 24(1): 6-18, ene.-jun. 2022. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1407961

ABSTRACT

RESUMEN Los hidrocarburos aromáticos monocíclicos: benceno, tolueno, etilbenceno y xileno (BTEX), presentes en crudo y refinados de petróleo, hacen parte de los compuestos con más impacto en el medio ambiente y la salud humana, debido a su naturaleza cancerígena, mutagénica y altamente tóxica. Esta investigación tuvo como objetivo obtener y caracterizar bacterias capaces de degradar tolueno. Se realizaron tres muestreos de suelo contaminado con hidrocarburos del Valle del Cauca en tres condiciones: gasolinería, derrame accidental y taller mecánico. Se aislaron bacterias capaces de crecer en tolueno fase vapor como única fuente de carbono y se caracterizaron a nivel morfológico, bioquímico y molecular. Para la caracterización molecular se amplificó, secuenció y analizó con herramientas bioinformáticas el gen ribosomal 16S. Se evaluó la utilización de tolueno directo con concentración al 1% como única fuente de carbono. Se logró aislar 29 bacterias con capacidad de metabolizar tolueno. La caracterización bioquímica y molecular identificó a las bacterias aisladas de suelo contaminado como Pseudomonas y Stenotrophomonas. Las bacterias aisladas en el taller mecánico resultaron ser los microorganismos con mejor crecimiento en tolueno como fuente de carbono, poseen un gran potencial para ser utilizadas para fines de biorremediación de suelos y aguas contaminadas con tolueno.


ABSTRACT Monocyclic aromatic hydrocarbons: benzene, toluene, ethylbenzene, and xylene (BTEX), present in crude oil and refined petroleum products, they are the compounds with a big impact on the environment and human health, due to their carcinogenic, mutagenic, and highly toxic. This research aimed to obtain and characterize bacteria capable of degrading toluene. Three samples of soil contaminated with hydrocarbons were carried out in three different conditions: oil station, accidental oil spill, and mechanical workshop. Bacteria capable of growing in toluene vapor as the unique carbon source were isolated and characterized at a morphological, biochemical, and molecular level. For molecular characterization, the 16S ribosomal gene was amplified, sequenced, and analyzed with bioinformatic tools. The use of direct toluene with 1% concentration as the sole carbon source was evaluated. It was possible to isolate 29 bacteria with the capacity to metabolize toluene. Biochemical and molecular characterization identified bacteria isolated from contaminated soil as Pseudomonas and Stenotrophomonas. The isolated strains in the mechanical workshop were the microorganisms with the best growth in toluene as a carbon source, they have great potential to be used for the bioremediation of soils and waters with toluene pollution.

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