scholarly journals Changes in the taxonomic and functional structure of microbial communities during vegetable waste mixed silage fermentation

Author(s):  
Quanju Xiang ◽  
Juntao Zhang ◽  
Xiying Huang ◽  
Menggen Ma ◽  
Ke Zhao ◽  
...  

Silage fermentation, a sustainable way to use vegetable waste resources, is a complex process driven by a variety of microorganisms. We used lettuce waste as the main raw material for silage, analyzed changes in the physico-chemical characteristics and bacterial community composition of silage over a 60-day fermentation, identified differentially abundant taxa, predicted the functional profiles of bacterial communities, and determined the associated effects on the quality of silage. The biggest changes occurred in the early stage of silage fermentation. Changes in the physico-chemical characteristics included a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content. The numbers of lactic acid bacteria (LAB) increased and molds, yeasts and aerobic bacteria decreased. The bacterial communities and their predicted functions on day 0 were clearly different from those on day 7 to day 60. The relative abundances of phylum Firmicutes and genus Lactobacillus increased. Nitrite ammonification and nitrate ammonification were more prevalent after day 0. The differences in the predicted functions were associated with differences in pH and amino acid, protein, carbohydrate, NH3-N, ether extract and crude ash contents.

2020 ◽  
Author(s):  
Juntao Zhang ◽  
Xiying Huang ◽  
Menggen Ma ◽  
Quanju Xiang ◽  
Ke Zhao ◽  
...  

Abstract Background:Silage fermentation, a sustainable way to use vegetable waste resources, is a complex process driven by a variety of microorganisms. We used lettuce waste as the raw material for silage, analyzed changes in the physico-chemical characteristics and bacterial community composition of silage during a 60 day fermentation, identified differentially abundant taxa, predicted the functional profiles of bacterial communities, and determined the associated effects on the quality of silage. Results: The biggest changes occurred in the early stage of silage fermentation. Changes in the physico-chemical characteristics included a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content. The numbers of lactic acid bacteria increased and those of molds, yeasts and aerobic bacteria decreased. The bacterial communities and their predicted functions on day 0 were clearly different from those on day 7 to day 60. The relative abundances of phylum Firmicutes and genus Lactobacillus increased. Nitrite ammonification and nitrate ammonification were more prevalent after day 0. The differences in the predicted functions were associated with differences in pH and amino acid, protein, carbohydrate, NH3-N, ether extract and crude ash contents. Conclusion: Firmicutes and Lactobacillus were the dominant taxa during vegetable waste silage fermentation. The microbial communities and the predicted functions changed in different stages of silage fermentation, and the changes were accompanied with changes in the physico-chemical characteristics, especially with a decrease in pH and increases in ammonia nitrogen to total nitrogen ratio and lactic acid content.


1998 ◽  
Vol 64 (8) ◽  
pp. 2982-2987 ◽  
Author(s):  
Yimin Cai ◽  
Yoshimi Benno ◽  
Masuhiro Ogawa ◽  
Sadahiro Ohmomo ◽  
Sumio Kumai ◽  
...  

ABSTRACT Lactobacillus spp. from an inoculant andWeissella and Leuconostoc spp. from forage crops were characterized, and their influence on silage fermentation was studied. Forty-two lactic acid-producing cocci were obtained from forage crops and grasses. All isolates were gram-positive, catalase-negative cocci that produced gas from glucose, and produced more than 90% of their lactate in the d-isomer form. These isolates were divided into groups A and B by sugar fermentation patterns. Two representative strains from the two groups, FG 5 and FG 13, were assigned to the species Weissella paramesenteroides and Leuconostoc pseudomesenteroides, respectively, on the basis of DNA-DNA relatedness. Strains FG 5, FG 13, and SL 1 (Lactobacillus casei), isolated from a commercial inoculant, were used as additives to alfalfa and Italian ryegrass silage preparations. Lactic acid bacterium counts were higher in all additive-treated silages than in the control silage at an early stage of ensiling. During silage fermentation, inoculation with SL 1 more effectively inhibited the growth of aerobic bacteria and clostridia than inoculation with strain FG 5 or FG 13. SL 1-treated silages stored well. However, the control and FG 5- and FG 13-treated silages had a significantly (P < 0.05) higher pH and butyric acid and ammonia nitrogen contents and significantly (P < 0.05) lower lactate content than SL 1-treated silage. Compared with the control silage, SL 1 treatments reduced the proportion ofd-(−)-lactic acid, gas production, and dry matter loss in two kinds of silage, but the FG 5 and FG 13 treatments gave similar values in alfalfa silages and higher values (P < 0.05) in Italian ryegrass silage. The results confirmed that heterofermentative strains of W. paramesenteroides FG 5 andL. pseudomesenteroides FG 13 did not improve silage quality and may cause some fermentation loss.


Composting can be one of the solutions to tackle the issue of handling solid waste. In the present research work, a bench-scale vertical in-vessel aerobic composter was designed to stabilize the Devaraja market vegetable waste, Mysore using horse dung and plantain leaves as seeding material and bulking agent respectively. On average, Devaraja market generate 4.8-5.6 ton per day. Mix proportion of organic waste, bulking and seeding materials fed into composter was in the ratio of 5: 1: 0.5. Initial and variation in physico-chemical characteristics of waste were monitored during the composting period. The initial concentration of total nitrogen, phosphorous, total organic carbon and C/N ratio which was found to be 1.67%, 0.78%, 1.93%, 43.5% and 26 showed a variation of 2.4%, 1.1%, 2% 29% and 15 respectively at the end of 21 days of composting.


2021 ◽  
Author(s):  
Qiming Cheng ◽  
Liangyin Chen ◽  
Yulian Chen ◽  
Ping Li ◽  
Chao Chen

Abstract Background: Lactic acid bacteria have been proposed for the control of undesirable fermentation and subsequently aerobic deterioration due to their ability to produce antimicrobial metabolites in silage mass. To investigate the effect of specific LAB on silage fermentation characteristics and bacterial community composition of oat in cold region, silages were treated without additives (CK) or with three LAB strains (LB, Lactobacillus buchneri; nLP, low temperature tolerant Lactobacillus planrtarum; pLP, phenyllactic acid-producing Lactobacillus plantarum), and then stored at ambient temperature (< 20 ℃) for 30, 60 and 90 days. Results: Compared with CK, inoculation of LAB decreased final pH value, butyric acid content, ammonia-N of total N and dry matter loss of silage. Treatments with nLP and pLP increased (P < 0.05) lactic acid content, whereas LB increased (P < 0.05) acetic acid content of silage. Lactobacillus and Leuconstoc dominated in the silages with relative abundance of 68.29~96.63%. A prolonged storage period enhanced growth of Leuconstoc in pLP treated silage. In addition, pLP increased (P < 0.05) aerobic stability of silage as compared with nLP. Conclusions: In conclusion, inoculation of LAB improved silage fermentation and/or delayed aerobic deterioration by shifting bacterial community composition during ensiling. Phenyllactic acid-producing Lactobacillus plantarum as an inoculant exhibited potential for high quality silage production.


2021 ◽  
Author(s):  
Duowen Sa ◽  
Qiang Lu ◽  
Gentu Ge ◽  
Lin Sun ◽  
Yushan Jia

Abstract Background: The objective of this study was to evaluate the chemical compositions and microbial communities of salt-tolerant alfalfa silage. Salt-tolerant alfalfa was ensiled with no additive control, and cellulase for 30 and 60 to 90 days. In this study, the dry matter (DM) content of the raw material was 29.9% DM, and the crude protein (CP) content of the alfalfa was 21.9% CP. Results: After 30 days of fermentation, the DM content with the cellulase treatment was reduced by 3.6%, and the CP content was reduced by 12.7%. After 60 days of fermentation, compared with alfalfa raw material, the DM content in the control group (CK) was reduced by 1%, the CP content was reduced by 9.5%, and the WSC (water-soluble carbohydrates) content was reduced by 22.6%. With the cellulase, the lactic acid content of the 30- and 60-day silages was 2.66% DM and 3.48% DM. The content of Firmicutes in salinized alfalfa raw material was less than 0.1% of the total bacterial content. Before and after ensiling, the microbes had similar composition at the phylum level, and were composed of Firmicutes, Actinobacteria, Bacteroidetes, and Proteobacteria. The abundance of Pantoea was dominant in fresh alfalfa. In the absence of additives, after 30 days and 60 days of silage, the dominant lactic acid bacteria species became Lactococcus and Enterococcus. Conclusions: The results showed that LAB (Lactobacillus, Lactococcus, Enterococcus, and Pediococcus) played a major role in the fermentation of saline alfalfa silage. It also can better preserve the nutrients of saline alfalfa silage. The fermentation time would also change the microbial community of silage fermentation.


2011 ◽  
Vol 57 (No. 11) ◽  
pp. 493-498 ◽  
Author(s):  
S.J. Yang ◽  
Z.Y. Du ◽  
Y. Yu ◽  
Z.L. Zhang ◽  
X.Y. Sun ◽  
...  

The root system of six-year-old winter jujube (Zizyphus jujuba Mill. cv. Zhanhua) trees were manually pruned at 3, 5 or 7 times trunk diameter distance along both inter-row sides, to study the effects of root pruning on physico-chemical characteristics and biological properties of winter jujube rhizosphere soil. The results showed that the root pruning of 3 and 5 times trunk diameter distance increased the available nitrogen, phosphorus, potassium<sup><sup>[</sup></sup>concentrations and pH values in the rhizosphere soil and decreased organic matter concentrations, the contents of amino acids, organic acids and total sugars in the root exudates, the populations of bacteria, actinomyces and fungi, and inhibited the activities of catalase, invertase and urease enzymes in contrast to the control in early stage when root pruning was applied. The determined indexes presented a reverse trend as those in early stage after new roots appeared. Compared to the control, the trees by root pruning had higher pesticides residues of the rhizosphere soil in the whole experiment. No differences were noticed between 7 times trunk diameter distance and the control. It is proposed that root pruning had greater impacts on physico-chemical characteristics and biological properties of the rhizosphere soil depending on root pruning intensity. <br clear="all" /> &nbsp;


2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Naiara Ramos Ricardo ◽  
Marly Sayuri Katsuda ◽  
Luciana Fulaneto Maia ◽  
Lorena Fernandes Abrantes ◽  
Leila Matsunaga Oshiro

<p>The artisan cheese production is an important income source for family farmers, however the lack of standardization and negligence in the preparation of the product generates a low quality cheese. The production of cheese of good quality finds some obstacles, because milk does not contribute in many ways to ensure the characteristics of the product. The aim of this study was to evaluate the physico-chemical characteristics of 20 Minas Frescal cheeses, of which 10 samples were artisanal and 10 have industrial production. The handmade cheeses were sold in street markets and all the samples had no labeling and sanitary inspection seal. The industrialized were obtained in supermarkets, all the 20 samples were acquired in Londrina-PR. The analyses performed were &nbsp;moisture, fat (d.b.), pH and acidity. The fat analysis showed that 50% of samples from artisanal cheeses and 40% of industrialized ones violate the current laws. The pH of artisanal cheese samples ranged between 5.2 and 6.7 and the acidity ranged between 0.06 and 2.41%. The variation in acidity showed that the cheeses are made without standard and quality control of raw material. In industrialized cheeses the pH ranged between 5.3 and 6.5 and acidity between 0.2 and 1.4%. With this work we concluded that the small producers and industries do not pay attention to physico-chemical parameters essential to the quality of the cheese.</p><p>&nbsp;</p><p>DOI: http://dx.doi.org/10.14685/rebrapa.v2i2.48</p>


2021 ◽  
Vol 12 ◽  
Author(s):  
Miao Zhang ◽  
Lei Wang ◽  
Guofang Wu ◽  
Xing Wang ◽  
Haoxin Lv ◽  
...  

The corruption and/or poor quality of silages caused by low temperature and freeze-thaw conditions makes it imperative to identify effective starters and low temperature silage fermentation technology that can assist the animal feed industry and improve livestock productivity. The effect of L. plantarum QZ227 on the wheat silage quality was evaluated under conditions at constant low temperatures followed by repeated freezing and thawing at low temperatures. QZ227 became the predominant strain in 10 days and underwent a more intensive lactic acid bacteria fermentation than CK. QZ227 accumulated more lactic acid, but lower pH and ammonia nitrogen in the fermentation. During the repeated freezing and thawing process, the accumulated lactic acid in the silage fermented by QZ227 remained relatively stable. Relative to CK, QZ227 reduced the abundance of fungal pathogens in silage at a constant 5°C, including Aspergillus, Sporidiobolaceae, Hypocreaceae, Pleosporales, Cutaneotrichosporon, Alternaria, and Cystobasidiomycetes. Under varying low temperature conditions from days 40 to days 60, QZ227 reduced the pathogenic abundance of fungi such as Pichia, Aspergillus, Agaricales, and Plectosphaerella. QZ227 also reduced the pathogenic abundance of Mucoromycota after the silage had been exposed to oxygen. In conclusion, QZ227 can be used as a silage additive in the fermentation process at both constant and variable low temperatures to ensure fast and vigorous fermentation because it promotes the rapid accumulation of lactic acid, and reduces pH values and aerobic corruption compared to the CK.


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