scholarly journals β-Glucosidase genes differentially expressed during composting

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinyue Zhang ◽  
Bo Ma ◽  
Jiawen Liu ◽  
Xiehui Chen ◽  
Shanshan Li ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Environmental Changes ◽  
Cellulose Degradation ◽  
Degradation Mechanism ◽  
Degradation Process ◽  
Global Scale ◽  
Expression Of Genes ◽  
Glucose Tolerant ◽  
Cooling Phase ◽  
And Function

Abstract Background Cellulose degradation by cellulase is brought about by complex communities of interacting microorganisms, which significantly contribute to the cycling of carbon on a global scale. β-Glucosidase (BGL) is the rate-limiting enzyme in the cellulose degradation process. Thus, analyzing the expression of genes involved in cellulose degradation and regulation of BGL gene expression during composting will improve the understanding of the cellulose degradation mechanism. Based on our previous research, we hypothesized that BGL-producing microbial communities differentially regulate the expression of glucose-tolerant BGL and non-glucose-tolerant BGL to adapt to the changes in cellulose degradation conditions. Results To confirm this hypothesis, the structure and function of functional microbial communities involved in cellulose degradation were investigated by metatranscriptomics and a DNA library search of the GH1 family of BGLs involved in natural and inoculated composting. Under normal conditions, the group of non-glucose-tolerant BGL genes exhibited higher sensitivity to regulation than the glucose-tolerant BGL genes, which was suppressed during the composting process. Compared with the expression of endoglucanase and exoglucanase, the functional microbial communities exhibited a different transcriptional regulation of BGL genes during the cooling phase of natural composting. BGL-producing microbial communities upregulated the expression of glucose-tolerant BGL under carbon catabolite repression due to the increased glucose concentration, whereas the expression of non-glucose-tolerant BGL was suppressed. Conclusion Our results support the hypothesis that the functional microbial communities use multiple strategies of varying effectiveness to regulate the expression of BGL genes to facilitate adaptation to environmental changes.

scholarly journals β-glucosidase genes differentially expressed during composting

2020 ◽  
Author(s):  
Xinyue Zhang ◽  
Xiehui Chen ◽  
Shanshan Li ◽  
Erlie Su ◽  
Jiawen Liu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Cellulose Degradation ◽  
Degradation Mechanism ◽  
Microbial Community Composition ◽  
Global Scale ◽  
High Concentration ◽  
Down Regulation ◽  
Expression Of Genes ◽  
Glucose Tolerant ◽  
Functional Microbial Community

Abstract Background: Cellulose degradation by cellulase is brought about by complex communities of interacting microorganism, which significantly to the cycling of carbon on a global scale. β-Glucosidase is the rate-limiting enzyme of degradation of cellulose. Thus, analysis of expression of genes involved in cellulose degradation and regulation of β-glucosidase gene expression in composting is beneficial to a better understanding of cellulose degradation mechanism. According to our previous researches, we present the hypothesis that “microbial functional communities differentially regulate the expression of glucose-tolerant β-glucosidase and glucose sensitive β-glucosidase (up or down regulation) to adapt to the changes in cellulose degradation.” Results: Here, the functional microbial community structure and function change in association with cellulose degradation during the process of natural and inoculated composts was investigated by metatranscriptome and DNA clone library. Compared with inoculated compost, cellulose degradation was obviously inhibited during natural composting. Especially, the cooling phase of natural compost exhibited carbon catabolite repression (CCR) effect due to high concentration of glucose and cellobiose. The expression of genes encoding endoglucanase and exoglucanase were significantly down-regulation, while the CCR has no effect on β-glucosidase genes expression levels. But functional microbial community composition changed significantly, the composition of glucose-tolerant β-glucosidase increased. Conclusions: These results indicated that microbial functional communities differentially regulate the expression of glucose tolerant β-glucosidase (up regulation) and non-glucose tolerant β-glucosidase (down regulation) under CCR. This work provides a frame work to predict how functional microbial communities will respond to cellulose degradation conditions changes.

Molecular analyses of the diversity and function of the family 1 β-glucosidase-producing microbial community in compost

2021 ◽  
Author(s):  
Xinyue Zhang ◽  
Erlie Su ◽  
Shanshan Li ◽  
Xiehui Chen ◽  
Zhihua Fan ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Environmental Changes ◽  
Diversity Index ◽  
Cellulose Degradation ◽  
Principal Component ◽  
Dna And Rna ◽  
Functional Community ◽  
Genes Encoding ◽  
The Individual ◽  
And Function

The diversity and transcription efficiency of GH1 family β-glucosidase genes were investigated in natural and inoculated composts using a DNA clone library and real-time qPCR. Compositional differences were observed in the functional community between both composting processes. Proteobacteria, Actinobacteria, Firmicutes, and Chloroflexi were the dominant phyla. Twenty representative β-glucosidase genes were quantitatively analyzed from DNA and RNA pools. Principal component analysis and Pearson’s correlation analysis showed that cellulose degradation is correlated with the composition and succession of functional microbial communities, and this correlation was mainly observed in Proteobacteria and Actinobacteria. Compared with inoculated compost, the functional microbial communities in natural compost with a low diversity index exhibited weak buffering capacity for function in response to environmental changes. This may explain the consistency and dysfunction of cellulose degradation and transcriptional regulation by dominant β-glucosidase genes. Except for the β-glucosidase genes encoding constitutive enzymes, individual β-glucosidase genes responded to environmental changes more drastically than the group β-glucosidase genes. Correlation results suggested that β-glucosidase genes belonging to Micrococcales played an important role in the regulation of intracellular β-glucosidase. These results indicated that the responses of functional microorganisms were different during both composting processes, and were reflected at both the individual and group levels.

scholarly journals Mechanism of differential expression of β-glucosidase genes in functional microbial communities in response to carbon catabolite repression

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Xinyue Zhang ◽  
Xiehui Chen ◽  
Shanshan Li ◽  
Ayodeji Bello ◽  
Jiawen Liu ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Differential Expression ◽  
Carbon Metabolism ◽  
Catabolite Repression ◽  
Carbon Catabolite Repression ◽  
Regulatory Mechanism ◽  
Glucose Tolerant ◽  
And Function ◽  
Functional Microbial Community

Abstract Background β-Glucosidase is the rate-limiting enzyme of cellulose degradation. It has been stipulated and established that β-glucosidase-producing microbial communities differentially regulate the expression of glucose/non-glucose tolerant β-glucosidase genes. However, it is still unknown if this differential expression of functional microbial community happens accidentally or as a general regulatory mechanism, and of what biological significance it has. To investigate the composition and function of microbial communities and how they respond to different carbon metabolism pressures and the transcriptional regulation of functional genes, the different carbon metabolism pressure was constructed by setting up the static chamber during composting. Results The composition and function of functional microbial communities demonstrated different behaviors under the carbon metabolism pressure. Functional microbial community up-regulated glucose tolerant β-glucosidase genes expression to maintain the carbon metabolism rate by enhancing the transglycosylation activity of β-glucosidase to compensate for the decrease of hydrolysis activity under carbon catabolite repression (CCR). Micrococcales play a vital role in the resistance of functional microbial community under CCR. The transcription regulation of GH1 family β-glucosidase genes from Proteobacteria showed more obvious inhibition than other phyla under CCR. Conclusion Microbial functional communities differentially regulate the expression of glucose/non-glucose tolerant β-glucosidase genes under CCR, which is a general regulatory mechanism, not accidental. Furthermore, the differentially expressed β-glucosidase gene exhibited species characteristics at the phylogenetic level.

Effects of Maternal Obesity and Gestational Diabetes Mellitus on the Placenta: Current Knowledge and Targets for Therapeutic Interventions

2020 ◽  
Vol 19 (2) ◽  
pp. 176-192
Author(s):  
Samantha Bedell ◽  
Janine Hutson ◽  
Barbra de Vrijer ◽  
Genevieve Eastabrook
Keyword(s):  
Diabetes Mellitus ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Maternal Obesity ◽  
Environmental Changes ◽  
Current Knowledge ◽  
Therapeutic Interventions ◽  
Placental Development ◽  
Exchange Site ◽  
And Function

: Obesity and gestational diabetes mellitus (GDM) are becoming more common among pregnant women worldwide and are individually associated with a number of placenta-mediated obstetric complications, including preeclampsia, macrosomia, intrauterine growth restriction and stillbirth. The placenta serves several functions throughout pregnancy and is the main exchange site for the transfer of nutrients and gas from mother to fetus. In pregnancies complicated by maternal obesity or GDM, the placenta is exposed to environmental changes, such as increased inflammation and oxidative stress, dyslipidemia, and altered hormone levels. These changes can affect placental development and function and lead to abnormal fetal growth and development as well as metabolic and cardiovascular abnormalities in the offspring. This review aims to summarize current knowledge on the effects of obesity and GDM on placental development and function. Understanding these processes is key in developing therapeutic interventions with the goal of mitigating these effects and preventing future cardiovascular and metabolic pathology in subsequent generations.

A Crucial Role for Diet in the Relationship Between Gut Microbiota and Cardiometabolic Disease

2020 ◽  
Vol 71 (1) ◽  
pp. 149-161 ◽  
Author(s):  
Ilias Attaye ◽  
Sara-Joan Pinto-Sietsma ◽  
Hilde Herrema ◽  
Max Nieuwdorp
Keyword(s):  
Gut Microbiota ◽  
Global Scale ◽  
Cardiometabolic Disease ◽  
Microbiota Composition ◽  
Dietary Interventions ◽  
Fermentable Carbohydrates ◽  
Cost Efficient ◽  
And Function ◽  
Gut Microbiota Composition

Cardiometabolic disease (CMD), such as type 2 diabetes mellitus and cardiovascular disease, contributes significantly to morbidity and mortality on a global scale. The gut microbiota has emerged as a potential target to beneficially modulate CMD risk, possibly via dietary interventions. Dietary interventions have been shown to considerably alter gut microbiota composition and function. Moreover, several diet-derived microbial metabolites are able to modulate human metabolism and thereby alter CMD risk. Dietary interventions that affect gut microbiota composition and function are therefore a promising, novel, and cost-efficient method to reduce CMD risk. Studies suggest that fermentable carbohydrates can beneficially alter gut microbiota composition and function, whereas high animal protein and high fat intake negatively impact gut microbiota function and composition. This review focuses on the role of macronutrients (i.e., carbohydrate, protein, and fat) and dietary patterns (e.g., vegetarian/vegan and Mediterranean diet) in gut microbiota composition and function in the context of CMD.

scholarly journals Investigation of the β-pinene photooxidation by OH in the atmosphere simulation chamber SAPHIR

2016 ◽  
Author(s):  
Martin Kaminski ◽  
Hendrik Fuchs ◽  
Ismail-Hakki Acir ◽  
Birger Bohn ◽  
Theo Brauers ◽  
...  
Keyword(s):  
Degradation Mechanism ◽  
Degradation Process ◽  
Product Distribution ◽  
High Reactivity ◽  
Oxidation Products ◽  
Chemical Mechanism ◽  
Emission Rates ◽  
Photochemical Degradation ◽  
Atmosphere Simulation Chamber ◽  
Simulation Chamber

Abstract. Beside isoprene, monoterpenes are the non-methane volatile organic compounds (VOC) with the highest global emission rates. Due to their high reactivity towards OH, monoterpenes can dominate the radical chemistry of the atmosphere in forested areas. In the present study the photochemical degradation mechanism of β-pinene was investigated in the Jülich atmosphere simulation chamber SAPHIR. The focus of this study is on the OH budget in the degradation process. Therefore the SAPHIR chamber was equipped with instrumentation to measure radicals (OH, HO2, RO2), the total OH reactivity, important OH precursors (O3, HONO, HCHO), the parent VOC beta-pinene, its main oxidation products, acetone and nopinone, and photolysis frequencies. All experiments were carried out under low NOx conditions (≤ 2 ppb) and at atmospheric beta-pinene concentrations (≤ 5 ppb) with and without addition of ozone. For the investigation of the OH budget, the OH production and destruction rates were calculated from measured quantities. Within the limits of accuracy of the instruments, the OH budget was balanced in all β-pinene oxidation experiments. However, even though the OH budget was closed, simulation results from the Master Chemical Mechanism 3.2 showed that the OH production and destruction rates were underestimated by the model. The measured OH and HO2 concentrations were underestimated by up to a factor of two whereas the total OH reactivity was slightly overestimated because of the poor reproduction of the measured nopinone by the model by up to a factor of three. A new, theory-derived first-generation product distribution by Vereecken and Peeters was able to reproduce the measured nopinone time series and the total OH reactivity. Nevertheless the measured OH and HO2 concentrations remained underestimated by the numerical simulations. These observations together with the fact that the measured OH budget was closed suggest the existence of unaccounted sources of HO2.

scholarly journals Dynamics of microbial communities during decomposition of litter from pioneering plants in initial soil ecosystems

2013 ◽  
Vol 10 (7) ◽  
pp. 5115-5124 ◽  
Author(s):  
J. Esperschütz ◽  
C. Zimmermann ◽  
A. Dümig ◽  
G. Welzl ◽  
F. Buegger ◽  
...  
Keyword(s):  
Microbial Community ◽  
Food Web ◽  
Microbial Communities ◽  
Litter Quality ◽  
Degradation Process ◽  
Mining Area ◽  
Plant Litter ◽  
Litter Addition ◽  
Fungal Abundance ◽  
Soil Ecosystems

Abstract. In initial ecosystems, concentrations of all macro- and micronutrients can be considered as extremely low. Plant litter therefore strongly influences the development of a degrader's food web and is an important source for C and N input into soil in such ecosystems. In the present study, a 13C litter decomposition field experiment was performed for 30 weeks in initial soils from a post-mining area near the city of Cottbus (Germany). Two of this region's dominant but contrasting pioneering plant species (Lotus corniculatus L. and Calamagrostis epigejos L.) were chosen to investigate the effects of litter quality on the litter decomposing microbial food web in initially nutrient-poor substrates. The results clearly indicate the importance of litter quality, as indicated by its N content, its bioavailability for the degradation process and the development of microbial communities in the detritusphere and soil. The degradation of the L. corniculatus litter, which had a low C / N ratio, was fast and showed pronounced changes in the microbial community structure 1–4 weeks after litter addition. The degradation of the C. epigejos litter material was slow and microbial community changes mainly occurred between 4 and 30 weeks after litter addition to the soil. However, for both litter materials a clear indication of the importance of fungi for the degradation process was observed both in terms of fungal abundance and activity (13C incorporation activity)

scholarly journals Effects of Lime Application and Understory Removal on Soil Microbial Communities in Subtropical Eucalyptus L’Hér. Plantations

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 338 ◽  
Author(s):  
Songze Wan ◽  
Zhanfeng Liu ◽  
Yuanqi Chen ◽  
Jie Zhao ◽  
Qin Ying ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Litter Decomposition ◽  
Decomposition Rate ◽  
Environmental Changes ◽  
Soil Microbial Communities ◽  
Dissolved Carbon ◽  
Soil Microbial ◽  
Litter Decomposition Rate ◽  
Eucalyptus Plantations ◽  
Lime Application

Soil microorganisms play key roles in ecosystems and respond quickly to environmental changes. Liming and/or understory removal are important forest management practices and have been widely applied to planted forests in humid subtropical and tropical regions of the world. However, few studies have explored the impacts of lime application, understory removal, and their interactive effects on soil microbial communities. We conducted a lime application experiment combined with understory removal in a subtropical Eucalyptus L’Hér. plantation. Responses of soil microbial communities (indicated by phospholipid fatty acids, PLFAs), soil physico-chemical properties, and litter decomposition rate to lime and/or understory removal were measured. Lime application significantly decreased both fungal and bacterial PLFAs, causing declines in total PLFAs. Understory removal reduced the fungal PLFAs but had no effect on the bacterial PLFAs, leading to decreases in the total PLFAs and in the ratio of fungal to bacterial PLFAs. No interaction between lime application and understory removal on soil microbial community compositions was observed. Changes in soil microbial communities caused by lime application were mainly attributed to increases in soil pH and NO3–-N contents, while changes caused by understory removal were mainly due to the indirect effects on soil microclimate and the decreased soil dissolved carbon contents. Furthermore, both lime application and understory removal significantly reduced the litter decomposition rates, which indicates the lime application and understory removal may impact the microbe-mediated soil ecological process. Our results suggest that lime application may not be suitable for the management of subtropical Eucalyptus plantations. Likewise, understory vegetation helps to maintain soil microbial communities and litter decomposition rate; it should not be removed from Eucalyptus plantations.

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