scholarly journals Obtainment of Lignocellulose Degradation Microbial Community: The Effect of Acid-Base Combination After Restrictive Enrichment

Author(s):  
Binbin Hua ◽  
Xiaofen Wang ◽  
Zongjun Cui

Abstract Acid-base combination is used in some cases expecially after restricted enrichment, and has created many lignocellulose-degrading communities. While how it worked is not well understood. In this study, compost was used as inoculum source. Induced community structure changes were analyzed with high throughput sequencing to elucidate the formation processes and determine the mechanisms of acid-base combination. We found that after restricted enrichment, retaining primarily bacteria not only included that could decompose and utilize lignocellulose, such as Clostridium and Pseudomonas, but also synergistic microbiota such as Pseudoxanomonas and Alkalobacillaceae. When the proportion of these two types of bacteria was not balanced, the degradation ability of the microbial community was low or pH changes of it did not compound regular changes , which maybe lead to the failure of restricted enrichment. Microbial communities were re-constituted by acid-base combination, whereby the degrading and synergistic strains were adjusted to a more appropriate proportion. Acid-base combination fixed the instability of microbial communities caused by randomness of restrictive screening enrichment. In this study, the mechanism of acid-base combination was analyzed, which enriched the theoretical system of restricted culture, and provided an effective and controllable technical method for obtaining high-quality lignocellulose-degrading microbial community resources.

2021 ◽  
Vol 12 ◽  
Author(s):  
Mads Borgbjerg Jensen ◽  
Nadieh de Jonge ◽  
Maja Duus Dolriis ◽  
Caroline Kragelund ◽  
Christian Holst Fischer ◽  
...  

The enzymatic hydrolysis of lignocellulosic polymers is generally considered the rate-limiting step to methane production in anaerobic digestion of lignocellulosic biomass. The present study aimed to investigate how the hydrolytic microbial communities of three different types of anaerobic digesters adapted to lignocellulose-rich wheat straw in continuous stirred tank reactors operated for 134 days. Cellulase and xylanase activities were monitored weekly using fluorescently-labeled model substrates and the enzymatic profiles were correlated with changes in microbial community compositions based on 16S rRNA gene amplicon sequencing to identify key species involved in lignocellulose degradation. The enzymatic activity profiles and microbial community changes revealed reactor-specific adaption of phylogenetically different hydrolytic communities. The enzymatic activities correlated significantly with changes in specific taxonomic groups, including representatives of Ruminiclostridium, Caldicoprobacter, Ruminofilibacter, Ruminococcaceae, Treponema, and Clostridia order MBA03, all of which have been linked to cellulolytic and xylanolytic activity in the literature. By identifying microorganisms with similar development as the cellulase and xylanase activities, the proposed correlation method constitutes a promising approach for deciphering essential cellulolytic and xylanolytic microbial groups for anaerobic digestion of lignocellulosic biomass.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lauren M. Lui ◽  
Erica L.-W. Majumder ◽  
Heidi J. Smith ◽  
Hans K. Carlson ◽  
Frederick von Netzer ◽  
...  

Over the last century, leaps in technology for imaging, sampling, detection, high-throughput sequencing, and -omics analyses have revolutionized microbial ecology to enable rapid acquisition of extensive datasets for microbial communities across the ever-increasing temporal and spatial scales. The present challenge is capitalizing on our enhanced abilities of observation and integrating diverse data types from different scales, resolutions, and disciplines to reach a causal and mechanistic understanding of how microbial communities transform and respond to perturbations in the environment. This type of causal and mechanistic understanding will make predictions of microbial community behavior more robust and actionable in addressing microbially mediated global problems. To discern drivers of microbial community assembly and function, we recognize the need for a conceptual, quantitative framework that connects measurements of genomic potential, the environment, and ecological and physical forces to rates of microbial growth at specific locations. We describe the Framework for Integrated, Conceptual, and Systematic Microbial Ecology (FICSME), an experimental design framework for conducting process-focused microbial ecology studies that incorporates biological, chemical, and physical drivers of a microbial system into a conceptual model. Through iterative cycles that advance our understanding of the coupling across scales and processes, we can reliably predict how perturbations to microbial systems impact ecosystem-scale processes or vice versa. We describe an approach and potential applications for using the FICSME to elucidate the mechanisms of globally important ecological and physical processes, toward attaining the goal of predicting the structure and function of microbial communities in chemically complex natural environments.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1294
Author(s):  
Ning Wang ◽  
Qi Li ◽  
Mengqi Jiang ◽  
Weizhen Zhang ◽  
Hao Zhang ◽  
...  

This study investigated the effects of the mud-sinking (MS) method, agar gel-sinking (AS) method and agar gel-sinking with artificial aquatic mat (ASA) method on the growth, physiological characteristics, water purification capacity, and associated microbial community of the different organs of Vallisneria natans (V. natans). Results showed that the growth of agar-based growth (group AS and ASA) were more effective than the mud-wrapped method (group MS), exhibiting longer length, higher fresh weight and biomass of agar-based V. natans with the artificial aquatic mat (group ASA) being higher than those of other groups. MS caused a stress response in the oxidative system, which then inhibited photosynthesis. Results of water quality measurements showed that the three planting methods positively affected water purification without significant differences (p > 0.05). Besides, there was no significant difference (p > 0.05) between the microbial communities in terms of the roots and those found in rhizosphere soils in the MS group with high throughput sequencing. Meanwhile, the addition of agar in the AS and ASA groups increased the diversity of rhizosphere soil microbial communities and reduced the diversity of root microbial communities. Microbial community compositions in the rhizosphere soil and root differed significantly (p < 0.05). High throughput sequencing and scanning electron microscopy (SEM) also revealed that the biofilm on the surfaces were different, with Proteobacteria and Cyanophyta consistently dominating. This study provides new insights on the more effective revegetation methods of V. natans, researched the environmental impact of the addition of agar, and provides some theoretical support for the revegetation of submerged macrophytes under ecological restoration.


2020 ◽  
Vol 66 (11) ◽  
pp. 653-663 ◽  
Author(s):  
Shiwei Zhang ◽  
Yuan Wang ◽  
Xi Chen ◽  
Bingjian Cui ◽  
Zhihui Bai ◽  
...  

The dependence of plant health and crop quality on the epiphytic microbial community has been extensively addressed, but little is known about plant-associated microbial communities under natural conditions. In this study, the bacterial and fungal communities on grape leaves were analyzed by 16S rRNA gene and internal transcribed spacer high-throughput sequencing, respectively. The results showed differences in the composition of the microbial communities on leaf samples of nine wine grape varieties. The most abundant bacterial genus was Pseudomonas, and the top three varieties with Pseudomonas were Zinfandel (22.6%), Syrah (21.6%), and Merlot (13.5%). The most abundant fungal genus was Alternaria, and the cultivar with the lowest abundance of Alternaria was Zinfandel (33.6%), indicating that these communities had different habitat preferences. The linear discriminant analysis effect size of all species showed that the bacteria Enterococcus, Massilia, and Kocuria were significantly enriched on the leaves of Merlot, Syrah, Cabernet Sauvignon, respectively; Pseudomonadales and Pantoea on Zinfandel; and Bacillus, Turicibacter, and Romboutsia on Pinot Noir. Similarly, the fungi Cladosporium, Phoma, and Sporormiella were significantly enriched on Zinfandel, Lon, and Gem, respectively. Both Bray–Curtis and unweighted UniFrac revealed that bacteria and fungi have a significant impact (P < 0.01), and the results further proved that variety is the most important factor affecting the microbial community. The findings indicate that some beneficial or harmful microorganisms existing on the wine grape leaves might affect the health of the grape plants and the wine-making process.


2002 ◽  
Vol 68 (6) ◽  
pp. 3055-3066 ◽  
Author(s):  
Janet E. Hill ◽  
Robyn P. Seipp ◽  
Martin Betts ◽  
Lindsay Hawkins ◽  
Andrew G. Van Kessel ◽  
...  

ABSTRACT Complex microbial communities remain poorly characterized despite their ubiquity and importance to human and animal health, agriculture, and industry. Attempts to describe microbial communities by either traditional microbiological methods or molecular methods have been limited in both scale and precision. The availability of genomics technologies offers an unprecedented opportunity to conduct more comprehensive characterizations of microbial communities. Here we describe the application of an established molecular diagnostic method based on the chaperonin-60 sequence, in combination with high-throughput sequencing, to the profiling of a microbial community: the pig intestinal microbial community. Four libraries of cloned cpn60 sequences were generated by two genomic DNA extraction procedures in combination with two PCR protocols. A total of 1,125 cloned cpn60 sequences from the four libraries were sequenced. Among the 1,125 cloned cpn60 sequences, we identified 398 different nucleotide sequences encoding 280 unique peptide sequences. Pairwise comparisons of the 398 unique nucleotide sequences revealed a high degree of sequence diversity within the library. Identification of the likely taxonomic origins of cloned sequences ranged from imprecise, with clones assigned to a taxonomic subclass, to precise, for cloned sequences with 100% DNA sequence identity with a species in our reference database. The compositions of the four libraries were compared and differences related to library construction parameters were observed. Our results indicate that this method is an alternative to 16S rRNA sequence-based studies which can be scaled up for the purpose of performing a potentially comprehensive assessment of a given microbial community or for comparative studies.


2017 ◽  
Vol 2 (4) ◽  
pp. 350
Author(s):  
Zhuang Zhi Chen ◽  
Xiu Mei Wu ◽  
Yong Mei Shen ◽  
Cheng Gong Li ◽  
Kai Ge Xu ◽  
...  

<p><strong><em>Objective: </em></strong><em>The present study probes into the microbial community structure in Periplaneta americana under different breeding conditions, using 16S rRNA high-throughput sequencing technique, in the hope of finding the microbial community structure in Periplaneta americana and their diversity under different breeding conditions. </em></p><p><strong><em>Methods:</em></strong><em> In this study, we extract the microbial metagenomic DNA of 5 groups of Periplaneta americana which under different breeding conditions. Using lllumina Miseq sequencing platform, two-terminal sequencing of V3-V4 regions of 16S rRNA were sequenced; diversity of community structure was analyzed using the softwares such as fastqc, </em><em>QIIME, </em><em>PyNAST, fasttree and R language.</em></p><p><strong><em>Results: </em></strong><em>Shannon index of samples in SG group was lower than that of the other four groups, significantly lower than that of DB group (P&lt;0.05), but not significantly different from other groups. This suggested that the intake of a mixed fodder with high sugar, high fat and high protein by Periplaneta americana can reduce the diversity of microbial communities. Our findings showed that breeding intervention with different fodders may cause differences in the contents of Bacteroidetes, Proteobacteria and Firmicutes in Periplaneta americana. Results showed that long-term intake of lots of sucrose and fat may increase the proportion of Bacteroidetes in Periplaneta americana; and long-term intake of lots of sucrose may reduce the proportion of Proteobacteria in Periplaneta americana; and long-term intake of lots of fat may reduce the proportion of Firmicutes in Periplaneta americana. Two major dominant bacterial genera in all samples were Blattabacterium and Rickettsiella. But different feeding interventions can change the proportions of Blattabacterium and Rickettsiella.</em></p><p><strong><em>Conclusion:</em></strong><em> Periplaneta americana has a complex microbial community structure. Different feeding conditions may change the microbial community structure of Periplaneta americana. An important bacterial genus in Periplaneta americana, Blattabacterium is positively correlated with the intake of sucrose- and fat-rich fodder. In the breeding process of Periplaneta americana, adding sucrose and fat to fodder may increase the content and proportion of Blattabacterium in microbial communities.</em></p>


2021 ◽  
Author(s):  
Wan Tao ◽  
Rui Xu ◽  
Hanzhi Lin ◽  
Duanyi Huang ◽  
Pingzhou Su ◽  
...  

Abstract The extensive application of perfluoroalkyl and polyfluoroalkyl substances (PFASs) causes their frequent detection in various environments. Nevertheless, the effects of PFASs exposure on environmental microorganisms still remain unknown. In current work, two typical PFASs, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), are selected to investigate their long-term effects on soil microbes. Microbial community structure and diversity were investigated by high-throughput sequencing and multiple statistical methods. Under 90-days of exposure, PFAS treatments increased the alpha-diversity of soil microbial communities with PFOS treatment, followed by PFOA treatment. The long-term exposure of PFASs substantially changed the compositions of soil microbial communities. The most abundant phylum Proteobacteria decreased from 82.9% (without amended PFASs) to 62.1% (with PFOA treatment) and 77.8% (with PFOS treatment). As a comparison, the relative abundance of Bacteroidetes, Chloroflexi, Acidobacteria, and Ignavibacteriae increased in the PFOA or PFOS groups. Comparative co-occurrence networks were constructed to investigate the biotic interactions in the two treatments. It was found that most taxonomy nodes in the PFOA and PFOS networks were associated with the genus Hydrogenophaga and Pseudoxanthomonas, respectively. The LEfSe analysis identified a set of core taxonomies (e.g., Azospirillum, Methyloversatilis, Ancylobacter, Hydrogenophaga, and Methylomonas) in the soil microbial communities and suggested their different preferences to PFAS exposures. Functional gene prediction suggested that the microbial metabolism processes, such as nucleotide transport and metabolism, cell motility, carbohydrate transport and metabolism, energy production and conversion, and secondary metabolites biosynthesis transport and catabolism, might be significantly inhibited under PFAS exposure, which may further affect soil ecological services.


Environments ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 16
Author(s):  
Sergey Kharitonov ◽  
Mikhail Semenov ◽  
Alexander Sabrekov ◽  
Oleg Kotsyurbenko ◽  
Alena Zhelezova ◽  
...  

The role of methane as a greenhouse gas in the concept of global climate changes is well known. Methanogens and methanotrophs are two microbial groups which contribute to the biogeochemical methane cycle in soil, so that the total emission of CH4 is the balance between its production and oxidation by microbial communities. Traditional identification techniques, such as selective enrichment and pure-culture isolation, have been used for a long time to study diversity of methanogens and methanotrophs. However, these techniques are characterized by significant limitations, since only a relatively small fraction of the microbial community could be cultured. Modern molecular methods for quantitative analysis of the microbial community such as real-time PCR (Polymerase chain reaction), DNA fingerprints and methods based on high-throughput sequencing together with different “omics” techniques overcome the limitations imposed by culture-dependent approaches and provide new insights into the diversity and ecology of microbial communities in the methane cycle. Here, we review available knowledge concerning the abundances, composition, and activity of methanogenic and methanotrophic communities in a wide range of natural and anthropogenic environments. We suggest that incorporation of microbial data could fill the existing microbiological gaps in methane flux modeling, and significantly increase the predictive power of models for different environments.


2021 ◽  
Author(s):  
Qianwei Li ◽  
Lifeng Wang ◽  
Yamei Chen ◽  
Li Guo ◽  
Chengming You ◽  
...  

Abstract Aim The decomposition of plant residues is a fundamental process of soil organic matter accumulation. The loss of plant functional groups (PFGs) could affect this process by producing litter of different qualities in the soil. Microorganisms are one of the indispensable driving forces of ecological processes, but the mechanisms by microbial communities respond to aboveground PFG changes are still unclear, which limits our understanding of biogeochemical cycle changes under PFG loss.Methods We assessed the microbial taxonomic and functional composition of six typical single PFGs (evergreen conifer, evergreen shrubs, deciduous shrub, graminoid, forb and fern), random loss of a single PFG (SPFG) from litter mixtures and total mixture of six PFGs in a Tibetan fir forest by a high-throughput sequencing method.Results The microbial composition and function did not change with loss of a SPFG in litter, and microbial communities were mainly determined by the carbon and nitrogen ratio (C:N), carbon and phosphorus ratio (C:P), N and lignin, and bacterial functional pathways and fungal functional guilds were both determined by N, C:N and C:P ratios. Bacterial diversity was positively related while fungal diversity was negatively related to N and cellulose concentrations.Conclusion We speculated that the difference in initial litter qualities (especially C:N) between different PFGs, rather than a decreased number of PFGs, is a determinant of microbial composition and function. As the loss of PFG does not change litter quality, the microbial community can resist the loss of PFG, which maintains alpine ecosystem carbon and nutrient cycling stability.


2020 ◽  
Vol 48 (2) ◽  
pp. 399-409
Author(s):  
Baizhen Gao ◽  
Rushant Sabnis ◽  
Tommaso Costantini ◽  
Robert Jinkerson ◽  
Qing Sun

Microbial communities drive diverse processes that impact nearly everything on this planet, from global biogeochemical cycles to human health. Harnessing the power of these microorganisms could provide solutions to many of the challenges that face society. However, naturally occurring microbial communities are not optimized for anthropogenic use. An emerging area of research is focusing on engineering synthetic microbial communities to carry out predefined functions. Microbial community engineers are applying design principles like top-down and bottom-up approaches to create synthetic microbial communities having a myriad of real-life applications in health care, disease prevention, and environmental remediation. Multiple genetic engineering tools and delivery approaches can be used to ‘knock-in' new gene functions into microbial communities. A systematic study of the microbial interactions, community assembling principles, and engineering tools are necessary for us to understand the microbial community and to better utilize them. Continued analysis and effort are required to further the current and potential applications of synthetic microbial communities.


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