Growth Efficiency of Chlorella sorokiniana in Synthetic Media and Unsterilized Domestic Wastewater.

Incorporating a variety of microalgae into wastewater treatment is considered an economically viable and environmentally sound strategy. The present work assessed the growth characteristics of Chlorella sorokiniana during cultivation in balanced synthetic media and domestic wastewater. Increasing the NH4+-N concentration to 360 mg L-1 and adding extra PO43--P and SO42--S (up to 80 and 36 mg L-1, respectively) contributed to an increase in the total biomass levels (5.7-5.9 g L-1) during the cultivation of C. sorokiniana in synthetic media. Under these conditions, the maximum concentrations of chlorophylls and carotenoids were 180 ± 7.5 and 26 ± 1.4 mg L-1, respectively. Furthermore, when studying three types of domestic wastewaters, it was noted that only one wastewater contributed to the productive growth of C. sorokiniana, but all wastewaters stimulated an increased accumulation of protein. Finally, the alga, when growing in optimal unsterilized wastewater, showed a maximum specific growth rate of 0.73 day-1, a biomass productivity of 0.21 g L-1 day-1, and 100% NH4+-N removal. These results demonstrate that the tested alga actively adapts to changes in the composition of the growth medium and accumulates high levels of protein in systems with poor-quality water.

Magnetite Nanoparticles and Carbon Nanotubes for Improving the Operation of Mesophilic Anaerobic Digesters.

Anaerobic waste processing contributes to the development of the bioenergy sector and solves environmental problems. To date, many technologies have been developed for increasing the rate of the anaerobic digestion process and yield of methane. However, new technological advancements are required to eliminate biogas production inefficiencies. The performance of anaerobic digesters can be improved by adding conductive materials. In this study, the effects of the separate and shared use of magnetite nanoparticles and carbon nanotubes in anaerobic digesters converting high-nitrogen-containing waste, chicken manure, were investigated. The tested nanomaterials accelerated the methane production and increased the decomposition of products from the acidogenesis and acetogenesis stages. The combined use of magnetite nanoparticles and carbon nanotubes gave better results compared to using them alone or without them. Members of the bacterial classes Bacteroidia, Clostridia, and Actinobacteria were detected at higher levels in the anaerobic digesters, but in different proportions depending on the experiment. Representatives of the genera Methanosarcina, Methanobacterium, and Methanothrix were mainly detected within the methanogenic communities in the anaerobic digesters. The present study provides new data for supporting the anaerobic treatment of substrates with a high content of inhibitory compounds, such as chicken wastes.

Growth Parameters of Various Green Microalgae Species in Effluent from Biogas Reactors: The Importance of Effluent Concentration.

The use of liquid waste as a feedstock for cultivation of microalgae can reduce water and nutrient costs and can also be used to treat wastewater with simultaneous production of biomass and valuable products. This study applied strategies to treat diluted anaerobic digester effluent (ADE) as a residue of biogas reactors with moderate (87 ± 0.6 mg L-1; 10% ADE) and elevated NH4+-N levels (175 ± 1.1 mg L-1; 20% ADE). The effect of ADE dilution on the acclimatization of various microalgae was studied based on the analysis of the growth and productivity of the tested green algae. Two species of the genus Chlorella showed robust growth in the 10-20% ADE (with a maximum total weight of 3.26 ± 0.18 g L-1 for C. vulgaris and 2.81 ± 0.10 g L-1 for C. sorokiniana). The use of 10% ADE made it possible to cultivate the strains of the family Scenedesmaceae more effectively than the use of 20% ADE. The growth of Neochloris sp. in ADE was the lowest compared to other microalgal strains. The results of this study demonstrated the feasibility of introducing individual green microalgae into the processes of nutrient recovery from ADE to obtain biomass with a high protein content.

Anaerobic Digestion of Chicken Manure in the Presence of Magnetite, Granular Activated Carbon, and Biochar: Operation of Anaerobic Reactors and Microbial Community Structure.

The influence of magnetite nanoparticles, granular activated carbon (GAC), and biochar, as well as their combinations on the anaerobic digestion of chicken manure and the structure of microbial communities was studied. The addition of magnetite, GAC, and biochar increased the rate of methane production and the total methane yield. It has been observed that these additives stimulated anaerobic microorganisms to reduce the concentration of accumulated volatile organic acids. Various bacterial species within the classes Bacteroidia and Clostridia were found at higher levels in the anaerobic reactors but in different proportions depending on the experiment. Members of the genera Methanosarcina, Methanobacterium, Methanothrix, and Methanoculleus were mainly detected within the archaeal communities in the anaerobic reactors. Compared to the 16S rRNA gene-based study, the mcrA gene approach allowed a higher level of Methanosarcina in the system with GAC + magnetite to be detected. Based on our findings, the combined use of granular activated carbon and magnetite at appropriate dosages will improve biomethane production.

Growth Characteristics of Chlorella sorokiniana in a Photobioreactor during the Utilization of Different Forms of Nitrogen at Various Temperatures.

The cultivation of microalgae requires the selection of optimal parameters. In this work, the effect of various forms of nitrogen on the growth and productivity of Chlorella sorokiniana AM-02 when cultivated at different temperatures was evaluated. Regardless of the temperature conditions, the highest specific growth rate of 1.26 day-1 was observed in modified Bold's basal medium (BBM) with NH4+ as a nitrogen source, while the highest specific growth rate in BBM with NO3- as a nitrogen source achieved only 1.07 day-1. Moreover, C. sorokiniana grew well in medium based on anaerobic digester effluent (ADE; after anaerobic digestion of chicken/cow manure) with the highest growth rate being 0.92 day-1. The accumulation of proteins in algal cells was comparable in all experiments and reached a maximum of 42% of dry weight. The biomass productivity reached 0.41-0.50 g L-1 day-1 when cultivated in BBM, whereas biomass productivity of 0.32-0.35 g L-1 day-1 was obtained in ADE-based medium. The results, based on a bacterial 16S rRNA gene sequencing approach, revealed the growth of various bacterial species in ADE-based medium in the presence of algal cells (their abundance varied depending on the temperature regimen). The results indicate that biomass from C. sorokiniana AM-02 may be sustainable for animal feed production considering the high protein yields.

Assessment of Chlorella sorokiniana Growth in Anaerobic Digester Effluent.

Microalgae are considered a potential source of valuable compounds for multiple purposes and are potential agents for bioremediation of aquatic environments contaminated with different pollutants. This work evaluates the use of agricultural waste, unsterilized and anaerobically digested, to produce biomass from a strain of Chlorella sorokiniana. Furthermore, the presence of bacteria in these wastes was investigated based on the bacterial 16S rRNA gene sequencing. The results showed a specific growth rate ranging between 0.82 and 1.45 day-1, while the final biomass yield in different digestate-containing treatments (bacterial-contaminated cultures) ranged between 0.33 and 0.50 g L-1 day-1. Besides, substantial amounts of ammonium, phosphate, and sulfate were consumed by C. sorokiniana during the experimental period. The predominant bacteria that grew in the presence of C. sorokiniana in the effluent-containing treatments belonged to the genera Chryseobacterium, Flavobacterium, Sphingomonas, Brevundimonas, Hydrogenophaga, Sphingobacterium, and Pseudomonas. Therefore, this microalga can tolerate and grow in the presence of other microorganisms. Finally, these results show that anaerobically digested agricultural waste materials are a good substitute for growth media for green microalgae; however, phosphate and sulfate levels must also be controlled in the media to maintain adequate growth of microalgae.

Effect of magnetite on anaerobic digestion of distillers grains and beet pulp: Operation of reactors and microbial community dynamics.

It has been previously shown that magnetite (Fe3O4) nanoparticles stimulate the anaerobic digestion process in several anaerobic reactors. Here we evaluate the effect of magnetite nanoparticles on the efficiency of anaerobic digestion of distillers grains with solubles and sugar beet pulp in mesophilic batch experiments. The addition of magnetite nanopowder had a positive effect on the anaerobic digestion process. CH4 was produced faster in the presence of 50 mg of Fe3O4 per 1 g of added total solids than from treatments without addition of Fe3O4. These results demonstrate that the addition of magnetite enhances the methanogenic decomposition of organic acids. Microbial community structure and dynamics were investigated based on bacterial and archaeal 16S rRNA genes, as well as mcrA genes encoding the methyl-CoM reductase. Depending on the reactor, Bacteroides, midas_1138, Petrimonas, unclassified Rikenellaceae (class Bacteroidia), Ruminiclostridium, Proteiniclasticum, Herbinix, and Intestinibacter (class Clostridia) were the main representatives of the bacterial communities. The archaeal communities in well-performed anaerobic reactors were mainly represented by representatives of the genera Methanosarcina and Methanobacterium. Based on our findings, Fe3O4 nanoparticles, when used properly, will improve biomethane production.

Draft genome sequence of Clostridium jeddahense EE-R19 isolated from an anaerobic digester.

OBJECTIVES: Clostridium species of the order Clostridiales are mostly strictly anaerobic rod-shaped bacteria. They can be detected in a variety of environments, including the intestines of humans and animals, soil, water, and biogas reactors. Species of the genus Clostridium are widely used in various biotechnological processes, but several of them have been identified as significant human pathogens. Therefore, investigation at the genome level is necessary to provide valuable information about the ecology, genetics, and phylogenetic diversity of various Clostridium species. DATA DESCRIPTION: In the present study, we report the whole genome sequence of Clostridium jeddahense strain EE-R19, which was isolated from a mesophilic anaerobic digester. The draft genome of C. jeddahense EE-R19 consisted of 59 contigs (> 500 bp), which amounted to 3,562,974 with an overall G + C content of 51.79%. The whole genome shotgun project of C. jeddahense EE-R19 has been deposited at DDBJ/ENA/GenBank under the accession number JAAVNF000000000.

Comparison of the Photoautotrophic Growth Regimens of Chlorella sorokiniana in a Photobioreactor for Enhanced Biomass Productivity.

Microalgae have a wide industrial potential because of their high metabolic diversity and plasticity. Selection of optimal cultivation methods is important to optimize multi-purpose microalgal biotechnologies. In this research, Chlorella sorokiniana AM-02 that was isolated from a freshwater lake was cultured under various high photosynthetic photon flux density (PPFD) conditions and CO2 gas levels in standard Bold's basal medium (BBM). Furthermore, a wide range of nitrate levels (180-1440 mg L-1) was tested on the growth of C. sorokiniana. Microalgae growth, pigment concentration, medium pH, exit gas composition, as well as nitrate, phosphate, and sulfate levels were measured during an experimental period. The preferred high PPFD and optimal CO2 levels were found to be 1000-1400 µmol photons m-2 s-1 and 0.5-2.0% (v/v), respectively. The addition of nitrate ions (up to 1440 mg L-1) to the standard growth medium increased final optical density (OD750), cell count, pigment concentration, and total biomass yield but decreased the initial growth rate at high nitrate levels. Our findings can serve as the basis for a robust photoautotrophic cultivation system to maximize the productivity of large-scale microalgal cultures.

Comparison of the Microbiota and Inorganic Anion Content in the Saliva of Patients with Gastroesophageal Reflux Disease and Gastroesophageal Reflux Disease-Free Individuals.

The oral cavity is one of the most complex microbial environments; however, the complex nature of the salivary microbiota and the level of inorganic anions in the saliva of subjects with and without gastroesophageal reflux disease (GERD) are poorly understood. The primary goals of this pilot research were to assess differences in salivary bacterial community composition and inorganic anion concentrations between patients with GERD and GERD-free people. Thus, the salivary microbiota within both groups was dominated by these genera: Streptococcus, Prevotella, Porphyromonas, Veillonella, Neisseria, Haemophilus, Fusobacterium, Rothia, and Leptotrichia. However, the relative abundances of the genera Actinomyces, Atopobium, Stomatobaculum, Ruminococcaceae_[G-2], Veillonella, and Leptotrichia were significantly higher in the saliva samples of patients with GERD, while the genera Porphyromonas, Gemella, Peptostreptococcus, and Neisseria were less abundant in this group. The concentrations of chloride, phosphate, and sulphate ions in the human saliva varied among all subjects and sampling time. These results broaden our knowledge of the salivary microbial community composition and chemistry of saliva of patients with GERD and GERD-free individuals.

Draft genome sequence of Bacillus sp. EE-W1 isolated from a biogas reactor.

OBJECTIVES: The genus Bacillus comprises spore-forming rod-shaped Gram-positive bacteria, which usually grow aerobically or anaerobically. Members of this genus are common environmental microorganisms. Also, they can be monitored in the food production chain. Genome sequence of Bacillus sp. strain EE-W1 will provide helpful information to understand its ecology and genetics. Draft genome data may be useful in the field of using Bacillus species in industrial biotechnology. Also, these data can be a useful resource for the study of comparative genomics. DATA DESCRIPTION: Here, we present the draft genome sequence of Bacillus sp. strain EE-W1 isolated from a biogas reactor, Kazan, Russia. The assembled genome size was 5,769,164 bp, with a GC content 35.1%. This draft genome data can be accessed at DDBJ/ENA/GenBank under the accession WIPE00000000.

Spatial separation of metabolic stages in a tube anaerobic baffled reactor: reactor performance and microbial community dynamics.

Spatial separation of metabolic stages in anaerobic digesters can increase the methane content of biogas, as realized in a tube anaerobic baffled reactor. Here, we investigated the performance and microbial community dynamics of a laboratory-scale mesophilic anaerobic baffled reactor with four compartments treating an artificial substrate. Due to the activity of fermentative bacteria, organic acids mostly accumulated in the initial compartments. The methane content of the biogas increased while hydrogen levels decreased along the compartments. Microbial communities were investigated based on bacterial 16S rRNA genes, hydA genes encoding Fe-Fe-hydrogenases, and mcrA genes/transcripts encoding the methyl-CoM reductase. The metaproteome was analyzed to identify active metabolic pathways. During the reactor operation, Clostridia and Bacilli became most abundant in the first compartment. Later compartments were dominated by Sphingobacteriia, Deltaproteobacteria, Clostridia, Bacteroidia, Synergistia, Anaerolineae, Spirochaetes, vadinHA17, and W5 classes. Methanogenic communities were represented by Methanomicrobiales, Methanobacteriaceae, Methanosaeta, and Methanosarcina in the last compartments. Analysis of hydA and mcrA genes and metaproteome data confirmed the spatial separation of metabolic stages. In the first compartment, proteins of carbohydrate transport and metabolism were most abundant. Proteins assigned to coenzyme metabolism and transport as well as energy conservation dominated in the other compartments. Our study demonstrates how the spatial separation of metabolic stages by reactor design is underpinned by the adaptation of the microbial community to different niches.

Draft genome sequence of Staphylococcus sp. EZ-P03 isolated from a mesophilic anaerobic digester.

OBJECTIVES: Staphylococcus species of the family Staphylococcaceae are facultatively anaerobic Gram-positive cocci growing in clusters, pairs and occasionally in short chains. Staphylococci can be detected in different environments. They are common commensals, but some can also cause infections in humans. Hence, their investigation is required to understand ecology and genetics and to create an opportunity for comparative studies. DATA DESCRIPTION: In this study, we report the determination of a draft genome sequence of Staphylococcus sp. strain EZ-P03 which was isolated from anaerobically digested chicken waste materials. The draft genome of Staphylococcus sp. EZ-P03 constituted a total of 62 contigs (> 500 bp) amounting to 2,689,358 bp with a G+C content of 37.3% and a N50 contig size of 126,562 bp. The whole genome shotgun project of Staphylococcus sp. strain EZ-P03 has been deposited at DDBJ/ENA/GenBank under the accession number QPMO00000000.

Draft genome sequence of Bacillus pumilus strain EZ-C07 isolated from digested agricultural wastes.

OBJECTIVES: Bacillus species, belonging to the family Bacillaceae, are rod-shaped aerobic or facultative anaerobic Gram-positive bacteria that can be isolated from various environmental niches. Bacillus pumilus strains are resistant to unfavorable conditions such as UV, H2O2 and chemical disinfection. Furthermore, B. pumilus strains synthesize multifarious important enzymes and can be used in the production of some fermented foods, bioremediation of wastewater systems and biodegradation of environmental contaminants. Hence, investigation at the genomic level is required to understand their ecology, genetics and potential applications. DATA DESCRIPTION: In this research, we provide the genomic insights into one Bacillus species (EZ-C07) isolated from digested agricultural waste materials. The draft genome of the strain EZ-C07 consists of 3,724,869 bp with 3890 coding sequences and 41.5% G + C content. Based on 16S rRNA gene sequence analysis followed by in silico DNA-DNA hybridization studies, the strain EZ-C07 was identified as Bacillus pumilus belonging to the family Bacillaceae within the phylum Firmicutes. The whole genome shotgun project of B. pumilus strain EZ-C07 can be accessed at DDBJ/ENA/GenBank under the Accession QLVI00000000.

Comparison of intestinal bacterial and fungal communities across various xylophagous beetle larvae (Coleoptera: Cerambycidae).

The microbial gut communities associated with various xylophagous beetles offer great potential for different biotechnologies and elaboration of novel pest management strategies. In this research, the intestinal bacterial and fungal communities of various cerambycid larvae, including Acmaeops septentrionis, Acanthocinus aedilis, Callidium coriaceum, Trichoferus campestris and Chlorophorus herbstii, were investigated. The intestinal microbial communities of these Cerambycidae species were mostly represented by members of the bacterial phyla Proteobacteria and Actinobacteria and the fungal phylum Ascomycota. However, the bacterial and fungal communities varied by beetle species and between individual organisms. Furthermore, bacterial communities' metagenomes reconstruction indicated the genes that encode enzymes involved in the lignocellulose degradation (such as peroxidases, alpha-L-fucosidases, beta-xylosidases, beta-mannosidases, endoglucanases, beta-glucosidases and others) and nitrogen fixation (nitrogenases). Most of the predicted genes potentially related to lignocellulose degradation were enriched in the T. campestris, A. aedilis and A. septentrionis larval gut consortia, whereas predicted genes affiliated with the nitrogenase component proteins were enriched in the T. campestris, A. septentrionis and C. herbstii larval gut consortia. Several bacteria and fungi detected in the current work could be involved in the nutrition of beetle larvae.

Fungal, Bacterial, and Archaeal Diversity in the Digestive Tract of Several Beetle Larvae (Coleoptera).

Interpretation of how partnerships between fungi, bacteria, archaea, and insects are maintained through the life of the hosts is a big challenge within the framework of symbiosis research. The main goal of this work was to characterize the gut microbiota in larvae of several Coleoptera species using sequencing of the bacterial and archaeal 16S rRNA genes and fungal internal transcribed spacer (ITS) region. Thus, larvae with various food preferences, including Amphimallon solstitiale, Oryctes nasicornis, Cucujus cinnaberinus, Schizotus pectinicornis, Rhagium mordax, and Rhagium inquisitor, were thoroughly investigated in this work. We revealed an association of these beetle species mainly with four bacterial phyla, Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes, as well as with three fungal phyla, Ascomycota, Zygomycota, and Basidiomycota, but microbial communities varied depending on the beetle host, individual organism, and surrounding environment. Moreover, archaea within the phyla Euryarchaeota and Crenarchaeota in the hindgut content of O. nasicornis and A. solstitiale were additionally detected. The identified microbial communities suggest their potential role in the exploitation of various resources, providing nutritional needs for the host organism. These microorganisms can also represent a valuable source of novel metabolic capacities for their application in different biotechnologies.

Draft genome sequence of Brevibacterium epidermidis EZ-K02 isolated from nitrocellulose-contaminated wastewater environments.

Brevibacterium spp. are aerobic, nonbranched, asporogenous, gram-positive, rod-shaped bacteria which may exhibit a rod-coccus cycle when cells get older and can be found in various environments. ​Several Brevibacterium species have industrial importance and are capable of biotransformation of various contaminants. Here we describe the draft genome sequence of Brevibacterium epidermidis EZ-K02 isolated from nitrocellulose-contaminated wastewater environments. The genome comprises 3,885,924 bp, with a G + C content of 64.2%. This whole genome shotgun project has been deposited at DDBJ/ENA/GenBank under the accession PDHL00000000.

Draft genome sequence data and analysis of Brachybacterium sp. strain EE-P12 isolated from a laboratory-scale anaerobic reactor.

The species of the genus Brachybacterium belonging to the family Dermabacteraceae within the phylum Actinobacteria are gram-positive, facultatively anaerobic or aerobic, nonmotile and nonsporeforming bacteria. Cells of Brachybacterium spp. vary in shape from coccoid forms (stationary phase) to rods (exponential phase). Brachybacterium species can be isolated from numerous sources such as poultry deep litter, human gut, soil, food products. Here we describe the draft genome sequence of Brachybacterium sp. EE-P12 that was isolated from a laboratory-scale anaerobic digester. The genome sequencing generated 3,964,988 bp, with a G+C content of 72.2%. This draft genome data has been deposited at DDBJ/ENA/GenBank under the accession number QXCP00000000 (https://www.ncbi.nlm.nih.gov/nuccore/QXCP00000000).

Draft genome sequence of Paenibacillus sp. EZ-K15 isolated from wastewater systems.

OBJECTIVES: Paenibacillus species, belonging to the family Paenibacillaceae, are able to survive for long periods under adverse environmental conditions. Several Paenibacillus species produce antimicrobial compounds and are capable of biodegradation of various contaminants; therefore, more investigations at the genomic level are necessary to improve our understanding of their ecology, genetics, as well as potential biotechnological applications. DATA DESCRIPTION: In the present study, we describe the draft genome sequence of Paenibacillus sp. EZ-K15 that was isolated from nitrocellulose-contaminated wastewater samples. The genome comprises 7,258,662 bp, with a G+C content of 48.6%. This whole genome shotgun project has been deposited at DDBJ/ENA/GenBank under the accession PDHM00000000. Data demonstrated here can be used by other researchers working or studying in the field of whole genome analysis and application of Paenibacillus species in biotechnological processes.

Comparison of anaerobic digestion strategies of nitrogen-rich substrates: Performance of anaerobic reactors and microbial community diversity.

In the present study, the application of different operating strategies on performance of three continuous stirred tank reactors digesting chicken manure at mesophilic temperature and constant organic loading rate (OLR) of 3.5gVSL-1d-1 was investigated. Control reactor (RC) and reactor (RH) with the decreasing hydraulic retention time (HRT) had the comparable specific biogas production (SBP) with maximum values of 334-351mLg-1VS (added) during days 84-93, while the SBP from reactor with zeolites (RZ) was higher and achieved 426-432mLg-1VS (added). Attachments of microorganisms to zeolite particles as the operational environment, exchanged cations released from zeolites as well as lower total ammonium nitrogen (TAN) levels observed in RZ (6.2-6.3gL-1; days 71-93) compared to RC (6.6-6.9gL-1; days 71-93) resulted in a more effective process in RZ. Moreover, microbial community structure and dynamics were comprehensively characterized using Illumina sequencing, pyrosequencing and T-RFLP analysis of 16SrRNA genes. Methanogenic archaeal activity was additionally assessed by the expressed mcrA genes encoding the alpha subunit of methyl-CoM reductase. Within the major class Clostridia, Caldicoprobacter, Alkaliphilus, Gallicola, Sporanaerobacter and Tepidimicrobium spp. were the notable bacteria developed during operation of all tested reactors. Archaeal communities were dominated by methanogens belonging to the genus Methanosarcina followed by the genus Methanoculleus during the experimental period. Results of this study indicate that attachment of microorganisms to the zeolite particles as the operational environment might have led to the higher microbial activity at high ammonia concentrations.