title: Dynamics of bacterial communities during solid-state fermentation using agro-industrial wastes to produce poly-γ-glutamic acid, revealed by real-time PCR and denaturing gradient gel electrophoresis (DGGE).
abstract: The dynamics of bacterial communities play an important role in solid-state fermentation (SSF). Poly-γ-glutamic acid (γ-PGA) was produced by Bacillus amyloliquefaciens C1 in SSF using dairy manure compost and monosodium glutamate production residuals as basic substrates. The production of γ-PGA reached a maximum of 0.6% after 20 days fermentation. Real-time polymerase chain reaction showed the amount of total bacteria reached 3.95 × 10(9) 16S rDNA copies/g sample after 30 days, which was in good accordance with the 4.80 × 10(9) CFU/g obtained by plate counting. Denaturing gradient gel electrophoresis profile showed a reduction of microbial diversity during fermentation, while the inoculum, B. amyloliquefaciens C1, was detected as the dominant organism through the whole process. In the mesophilic phase of SSF, Proteobacteria was the dominant microbial, which was replaced by Firmicutes and Actinobacteria in the thermophilic phase. The molecular analysis of the bacterial diversity has significant potential for instructing the maturing process of SSF to produce γ-PGA at a large-scale level, which could be a benefit in the production of high quality and stable SSF products.
authors.affiliation: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Yong
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Cui
authors.forename: Lihua
authors.initials: L
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Ran
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
authors.forename: Xingming
authors.initials: X
authors.lastname: Yang
mesh_terms: D044822:Biodiversity; D015169:Colony Count, Microbial; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D058645:Denaturing Gradient Gel Electrophoresis; D005285:Fermentation; D006094:Gram-Positive Bacteria / Q000254:growth & development* / Q000378:metabolism*; D007220:Industrial Waste; D011099:Polyglutamic Acid / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D012970:Sodium Glutamate / Q000378:metabolism
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S; D011099:Polyglutamic Acid; D012970:Sodium Glutamate