Enhanced pollutant removal from rural non-point source wastewater using a two-stage multi-soil-layering system with blended carbon sources: Insights into functional genes, microbial community structure and metabolic function

Abstract Aim Soil microbial community structure and functional genes are critical to the cycling of carbon and nutrients in forest soils. As afforestation practices increasingly promote different functional traits tree species, it becomes critical to understand how they influences soil microbial community structures and functional genes, which directly influence soil biogeochemical processes. Methods We used fungi ITS and bacteria 16S rDNA to investigate soil microbial communities and functional genes in three monoculture plantations consisting of a non-native evergreen conifer (Pinus sibirica), a native deciduous conifer (Larix gmelinii), and a native deciduous angiosperm (Betula platyphylla) to compare with two 1:1 mixed-species plantations (P. sibirica and L. gmelinii, P. sibirica and B. platyphylla).Results The fungal community structure of the conifer-angiosperm mixed plantation was similar to that of the non-native evergreen conifer, and the bacterial community structure was similar to that of the angiosperm monoculture plantation. Fungal communities were strongly related to tree species, but bacteria communities were strongly related to soil nitrogen. Microbial co-occurrence patterns varied according to plantation types and altered soil nutrient cycling. Microbial communities in forest plantations of conifer-angiosperm mixed plantation contribute to soil nitrogen fixation and coniferous mixed plantation contribute to soil carbon fixation. Conclusions Our results provide a comparative study of the soil microbial ecology in afforestation of different functional trains species. This knowledge enhances the understanding of the relative control of soil microbial community structure.

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Effects of bioporous carriers on the performance and microbial community structure in side-stream anaerobic membrane bioreactors

Canadian Journal of Microbiology ◽

10.1139/cjm-2019-0632 ◽

2020 ◽

Vol 66 (8) ◽

pp. 475-489 ◽

Cited By ~ 1

Author(s):

Bin Zhang ◽

Jiao Yue ◽

Yu Guo ◽

Taixin Liu ◽

Min Zhou ◽

...

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Community Structure ◽

Oxygen Demand ◽

Illumina Miseq ◽

Membrane Bioreactors ◽

Pollutant Removal ◽

Sludge Reduction ◽

Porous Carrier ◽

Side Stream

The aim of this study was to investigate the effects of a volcanic rock porous carrier (VRPC) on sludge reduction, pollutant removal, and microbial community structure in an anaerobic side-stream reactor (ASSR). Three lab-scale membrane bioreactors (MBRs), including an anoxic–oxic MBR, which served as the control (C-MBR), an ASSR-coupled MBR (A-MBR), and an A-MBR filled with VRPC (FA-MBR) were stably and simultaneously operated for 120 days. The effect of the three reactors on the removal of chemical oxygen demand (COD) was almost negligible (all greater than 95%), but the average removal efficiency of ammonium nitrogen, total nitrogen, and total phosphorus was significantly improved by the insertion of an ASSR, especially when the ASSR was filled with VRPC. Finally, A-MBR and FA-MBR achieved 16.2% and 26.4% sludge reduction rates, with observed sludge yields of 0.124 and 0.109 g mixed liquid suspended solids/g COD, respectively. Illumina MiSeq sequencing revealed that microbial diversity and richness were highest in the VRPC, indicating that a large number of microorganisms formed on the carrier surface in the form of a biofilm. Abundant denitrifying bacteria (Azospira, Comamonadaceae_unclassified, and Flavobacterium) were immobilized on the carrier biofilm, which contributed to increased nitrogen removal. The addition of a VRPC to the ASSR successfully immobilized abundant hydrolytic, fermentative, and slow-growing microorganisms, which all contributed to reductions in sludge yield.

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Composition and Physiological Profiling of Sprout-Associated Microbial Communities

Journal of Food Protection ◽

10.4315/0362-028x-65.12.1903 ◽

2002 ◽

Vol 65 (12) ◽

pp. 1903-1908 ◽

Cited By ~ 21

Author(s):

ANABELLE MATOS ◽

JAY L. GARLAND ◽

WILLIAM F. FETT

Keyword(s):

Community Structure ◽

Microbial Community ◽

Microbial Communities ◽

Microbial Community Structure ◽

Carbon Sources ◽

The Other ◽

Independent Effect ◽

Patterns Of Utilization ◽

Plate Counts ◽

Alfalfa Sprouts

The native microfloras of various types of sprouts (alfalfa, clover, sunflower, mung bean, and broccoli sprouts) were examined to assess the relative effects of sprout type and inoculum factors (i.e., sprout-growing facility, seed lot, and inoculation with sprout-derived inocula) on the microbial community structure of sprouts. Sprouts were sonicated for 7 min or hand shaken with glass beads for 2 min to recover native microfloras from the surface, and the resulting suspensions were diluted and plated. The culturable fraction was characterized by the density (log CFU/g), richness (e.g., number of types of bacteria), and diversity (e.g., microbial richness and evenness) of colonies on tryptic soy agar plates incubated for 48 h at 30°C. The relative similarity between sprout-associated microbial communities was assessed with the use of community-level physiological profiles (CLPPs) based on patterns of utilization of 95 separate carbon sources. Aerobic plate counts of 7.96 ± 0.91 log CFU/g of sprout tissue (fresh weight) were observed, with no statistically significant differences in microbial cell density, richness, or diversity due to sprout type, sprout-growing facility, or seed lot. CLPP analyses revealed that the microbial communities associated with alfalfa and clover sprouts are more similar than those associated with the other sprout types tested. Variability among sprout types was more extensive than any differences between microbial communities associated with alfalfa and clover sprouts from different sprout-growing facilities and seed lots. These results indicate that the subsequent testing of biocontrol agents should focus on similar organisms for alfalfa and clover, but alternative types may be most suitable for the other sprout types tested. The inoculation of alfalfa sprouts with communities derived from various sprout types had a significant, source-independent effect on microbial community structure, indicating that the process of inoculation alters the dynamics of community development regardless of the types of organisms involved.

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