Bacteria In Consortium Research Articles

Analysis of the endophytic microbiota of roots and culms of two commercial sugarcane cultivars inoculated with a synthetic microbial community

The adoption of bioinputs in agriculture has aroused great interest in recent years and, in this scenario, the inoculation of crops with synthetic microbial communities (SynComs) has shown to be promising. In sugarcane crop, inoculation with nitrogen-fixing bacteria (NFB) in consortium with arbuscular mycorrhizal fungi (AMF) has shown positive results on plant development and nutrition. However, considering that the microbiota plays a fundamental role in the growth and health of the host plant, especially the endophytes, which are closely associated, few studies have explored the effects of SynCom inoculation on the endophytic microbiota of sugarcane. This study aimed to evaluate the impact of SynCom inoculation on the structure of the endophytic microbiota of sugarcane. The results of the analyses revealed that the microbiota diversity remained unchanged due to the inoculation treatment, while differences in microbial communities were found between the two evaluated commercial cultivars, RB867515 and RB92579, and between the two plant organs, roots and culms, under field conditions at the end of the first crop growth cycle (~360 days). Furthermore, microbes specifically detected in roots or culms present potential valuable applications in sugarcane cultivation in the future. Altogether, our data support that the inoculated microorganisms exerted their beneficial effects during the initial stages of plant development, which opens up space for new research with SynComs in these primordial stages of cane cropping.

EVALUATION OF BACTERIA RESPONSIBLE FOR DECOLOURIZATION OF METHYLENE BLUE DYE IN SOIL

The discharge of textile effluents in open streams and land poses serious environmental problems. Even after physical and chemical treatment colour removal is not 100% achieved and hence it causes environmental pollution. The present study deals with examination and isolation of potential mycorrhizal soil bacteria responsible for decolorization of Methylene blue dye which is an azo dye. The results showed Bacillus haynesii strain NRRL B-41327 and Bacillus licheniformis strain DSM 13 were responsible for decolorization of Methylene blue dye in mycorrhizal soil. These gram positive, rod shaped bacteria in consortium exhibited 52.30 % colour removal efficiency. Potential of these bacteria can be further exploited for removal of residual dyes from textile effluents for restoration of ecosystem in an eco-friendly way which will be cost effective too.

Synergism of cellulolytic bacteria in consortium as starter culture agent “MOIYL” for fiber feed

The study aimed to examine the synergism of cellulolytic cellulosic consortium degrading cellulose as a fibrous starter culture agent. The study used streak plate method on nutrient agar medium [NA]. The isolated bacterial isolates were isolates of potential cellulolytic bacteria isolated from oil palm plantation waste, corn, and coconut wastes, namely: Bsp1, BJ1, BJ2, BP3, BP6, BP11, BP13, and BP16. The isolates were scratched on the nutrient agar medium [NA] and incubated for 24 hours. Observations were made there was a clear zone or inhibit zone between two isolates that intersect. The results showed that from 8 isolates tested 5 isolates can synergize well against other isolates. Conclusion: naturally, the cellulolytic isolate from oil palm waste, corn waste, and coconut waste can be consortium as starter culture agent “MOIYL” for fibrous feed.

Change of bacterial community structure during cellulose degradation by the microbial consortium

In order to clarify dynamic change of microbial community composition and to identify key functional bacteria in the cellulose degradation consortium, we studied several aspects of the biodegradation of filter papers and rice straws by the microbial consortium, the change of substrate degradation, microbial biomass and pH of fermentation broth. We extracted total DNA of the microbial consortium in different degradation stages for high-throughput sequencing of amplicons of bacterial 16 S rRNA genes. Based on the decomposition characteristics test, we defined the 12th, 72nd and 168th hours after inoculation as the initial stage, peak stage and end stage of degradation, respectively. The microbial consortium was mainly composed of 1 phylum, 2 classes, 2 orders, 7 families and 11 genera. With cellulose degradation, bacteria in the consortium showed different growth trends. The relative abundance of Brevibacillus and Caloramator decreased gradually. The relative abundance of Clostridium, Bacillus, Geobacillus and Cohnella increased gradually. The relative abundance of Ureibacillus, Tissierella, Epulopiscium was the highest in peak stage. The relative abundance of Paenibacillus and Ruminococcus did not change obviously in each stage. Above-mentioned 11 main genera all belonged to Firmicutes, which are thermophilic, broad pH adaptable and cellulose or hemicellulose degradable. During cellulose degradation by the microbial consortium, aerobic bacteria were dominant functional bacteria in the initial stage. However, the relative abundance of anaerobic bacteria increased gradually in middle and end stage, and replaced aerobic bacteria to become main bacteria to degrade cellulose.

Synergistic degradation of pyrene by five culturable bacteria in a mangrove sediment-derived bacterial consortium

A pyrene-degrading microbial consortium was obtained after enrichment with mangrove sediment collected from Thailand. Five cultivable bacteria (Mycobacterium spp. PO1 and PO2, Novosphingobium pentaromativorans PY1, Ochrobactrum sp. PW1, and Bacillus sp. FW1) were successfully isolated from the consortium. Draft genomes of them showed that two different morphotypes of Mycobacterium (PO1 and PO2), possessed a complete gene set for pyrene degradation. PY1 contained genes for phthalate assimilation via protocatechuate, a central intermediate, by meta-cleavage pathway, and PW1 possessed genes for protocatechuate degradation via ortho-cleavage pathway. The occurrence of biosurfactant-producing genes in FW1 suggests the involvement in enhancing the pyrene bioavailability. Biotransformation experiments revealed that Mycobacterium completely degraded 100mgL−1 pyrene within six days, whereas no significant degradation was observed with the others. Notably, PY1 and PW1 exhibited higher activity for protocatechuate degradation than the others. The artificially reconstructed consortia containing Mycobacterium with the other three strains (PY1, PW1 and FW1) showed three-fold higher degradation rate for pyrene than the individual Mycobacterium. The enhanced pyrene biodegradation achieved in the consortium was due to the cooperative interaction of bacterial mixture. Our findings showing that synergistic degradation of pyrene in the consortium will facilitate the application of the defined bacterial consortium in bioremediation.

Impact of silver nanoparticles on benthic prokaryotes in heavy metal-contaminated estuarine sediments in a tropical environment

Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potential to shape estuarine sediment bacterial community structure.

Metabolic profiling of biofilm bacteria known to cause microbial influenced corrosion

This study builds upon previous research that demonstrated the simplicity of obtaining metabolite profiles of bacteria in urban water networks, by using the metabolic profile of bacteria extracted from a reticulation pipe biofilm, which is known to cause microbial influenced corrosion (MIC). The extracellular metabolites of the isolated bacteria, and those bacteria in consortium, were analysed in isolation, and after exposure to low levels of copper. Applying chemometric analytical methodologies to the metabolomic data, we were able to better understand the profile of the isolated biofilm bacteria, which were differentiated according to their activity and copper exposure. It was found that the metabolic activity of the isolated bacteria and the bacteria in consortium varied according to the bacterium's ability to metabolise copper. This demonstrates the power of metabolomic techniques for the discrimination of water reticulation biofilms comprising similar bacteria in consortium, but undergoing different physico-chemical activities, such as corrosion and corrosion inhibition.

Exploring the potential of natural bacterial consortium to degrade mixture of dyes and textile effluent

Mixture of 8 textile dyes was degraded in nutrient broth by using natural bacterial consortium within 3.5 h at static condition. The same consortium effectively degraded textile industry effluent within 3 h. ADMI (American Dye Manufacturer’s Institute) value removal was 89% and 67% for dye mixture and industrial effluent, respectively. The optimum pH and temperature for the decolorization of dye mixture was found to be 5 and 50 °C, respectively. Significant induction of intracellular enzymes laccase, azo reductase, veratryl alcohol oxidase and DCIP (2,6-dichlorophenol-indophenol) reductase suggested their active role in dye decolorization. Presence of 6 bacteria in natural consortium obtained from textile dye disposal site was confirmed by using molecular techniques, namely, T-RFLP (Terminal Restriction Fragment Length Polymorphism) and TGGE (Temperature Gradient Gel Electrophoresis). The products formed after decolorization of dye mixture were analyzed by FTIR spectroscopy, HPLC, HPTLC and GC–MS.

Novel dark fermentation involving bioaugmentation with constructed bacterial consortium for enhanced biohydrogen production from pretreated sewage sludge

Abstract The present study summarizes the observations on various nutrient and seed formulation methods using sewage sludge that have been aimed at ameliorating the biohydrogen production potential. Pretreatment methods viz. , acid/base treatment, heat treatment, sterilization, freezing–thawing, microwave, ultrasonication and chemical supplementation were attempted on sludge. It was observed that pretreatment was essential not only to reduce the needless, competitive microbial load but also to improve the nutrient solublization of sludge. Heat treatment at 121 °C for 20 min was found to be most effective in reducing the microbial load by 98% and hydrolyzing the organic fraction of sludge. However, this pretreatment alone was either not sufficient or inconsistent in developing a suitable microbial consortium for hydrogen production. Hydrogen yield was found to improve 1.5–4 times upon inoculation with H 2 -producing microorganisms. A defined microbial consortium was developed consisting of three established bacteria viz., Enterobacter cloacae IIT-BT 08, Citrobacter freundii IIT-BT L139 and Bacillus coagulans IIT-BT S1. Following pretreatments soluble proteins and lipids (the major component of the sludge) were also found to be consumed besides carbohydrates. This laid out the concurrent proteolytic/lipolytic ability of the developed H 2 -producing consortium. 1:1:1 v/v ratio of these bacteria in consortium was found to give the maximum yield of H 2 from sludge, 39.15 ml H 2 /g COD reduced . 15%v/v dilution and supplementation with 0.5%w/v cane molasses prior to heat treatment was found to further improve the yield to 41.23 ml H 2 /g COD reduced .