Environmental sex reversal in parrotfish does not cause differences in the structure of their gut microbial communities.

Parrotfish are a common fish in coral reef areas, but little is known about their gut microbial communities. In addition, parrotfish are capable of sex reversal, usually some males are sexually reversed from females, and it is still not known whether this sex reversal leads to significant changes in gut microbial communities. In this study, we investigated the gut microbial communities of three species of parrotfish including Scarus forsteni (4 females and 4 sex-reversed males), Scarus ghobban (5 females and 5 sex-reversed males), and Hipposcarus longiceps (5 females and 5 sex-reversed males) by using high-throughput sequencing technology.

Comparative analyses on nitrogen removal microbes and functional genes within anaerobic-anoxic-oxic and deoxidation ditch sewage-treating processes in Wuhan and Xi'an cities, China.

Introduction: Anaerobic-anoxic-oxic (A/O) and deoxidation ditch (DOD) processes are being increasingly preferred owing to their effectiveness in treating various wastes in wastewater treatment plants (WWTPs). Considering seasonal variations is crucial in optimizing treatment processes, ensuring compliance with regulations, and maintaining the overall efficiency and effectiveness of WWTPs. This study aimed to determine the influence of seasonality on nitrogen removing microbes and functional genes within A/O and DOD processes in the humid Wuhan and semi-arid Xi'an cities, China.

Comparative analysis of microbial community under acclimation of linear alkylbenzene sulfonate (LAS) surfactants and degradation mechanisms of functional strains.

Linear alkylbenzene sulfonate (LAS) is one of the most widely used anionic surfactants and a common toxic pollutant in wastewater. This study employed high throughput sequencing to explore the microbial community structure within activated sludge exposed to a high concentration of LAS. Genera such as Pseudomonas, Aeromonas, Thauera and Klebsiella exhibited a significant positive correlation with LAS concentrations.

Denitrificimonas halotolerans sp. nov., a novel species isolated from UASB sludge treating landfill leachate.

A Gram-stain-negative, facultative anaerobe, rod-shaped strain JX-1 was isolated from UASB sludge treating landfill leachate in Wuhan, China. The isolate is capable of growing under conditions of pH 6.0-11.

Mitigating sediment cadmium contamination through combining PGPR Enterobacter ludwigii with the submerged macrophyte Vallisneria natans.

Sediment cadmium contamination poses risks to aquatic ecosystems. Phytoremediation is an environmentally sustainable method to mitigate cadmium contamination. Submerged macrophytes are affected by cadmium stress, but plant growth-promoting rhizobacteria (PGPR) can restore the health status of submerged macrophytes.

Submerged macrophyte restoration enhanced microbial carbon utilization in shallow lakes.

Submerged macrophytes are integral to the functioning of shallow lakes through their interaction with microorganisms. However, we have a limited understanding of how microbial communities in shallow lakes respond when macrophytes are restored after being historically extirpated. Here, we explored the interactions between prokaryotic communities and carbon utilization in two lakes where submerged macrophytes were restored.

gen. nov., sp. nov., a novel member of family isolated from activated sludge collected in Shenzhen, PR China.

A Gram-stain-negative, strictly aerobic and filamentous bacterial strain, designated as DQS-5, was isolated from the activated sludge of a municipal sewage treatment plant in Shenzhen, PR China. Optimal growth was observed at 28 °C and pH 7.5.

Antimony precipitation and removal by antimony hyper resistant strain Achromobacter sp. 25-M.

Microbes have been confirmed to play key role in biogeochemistry of antimony. However, the impact of indigenous bacteria (from active mines) on the behavior of dissolved antimony remained poorly understood. In current study, the hyper antimony-resistant strain, Achromobacter sp.

sp. nov., a novel member of isolated from activated sludge in Hefei, PR China.

A floc-forming bacterial strain, designated HF-7, was isolated from the activated sludge of an industrial wastewater treatment plant in Hefei, PR China. Cells of this strain were Gram-stain-positive, catalase- and oxidase-negative, facultatively anaerobic, and rod-shaped. Growth occurred at 20-42 °C (optimum, 28 °C), at pH 5.

Temperature-mediated microbial carbon utilization in China's lakes.

Microbes play an important role in aquatic carbon cycling but we have a limited understanding of their functional responses to changes in temperature across large geographic areas. Here, we explored how microbial communities utilized different carbon substrates and the underlying ecological mechanisms along a space-for-time substitution temperature gradient of future climate change. The gradient included 47 lakes from five major lake regions in China spanning a difference of nearly 15°C in mean annual temperatures (MAT).

gen. nov., sp. nov., a novel member of the family isolated from a coastal shrimp pond in Guangxi, PR China.

A Gram-stain-negative, strictly aerobic, rod-shaped and motile bacterium with bipolar flagella, designated G-43, was isolated from a surface seawater sample collected from an aquaculture in Guangxi, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain G-43 was most closely related to the family and distantly to the most closely related genera and (95.52 % and 94.

Characterization of the Positive Transcription Regulator PfaR for Improving Eicosapentaenoic Acid Production in Shewanella putrefaciens W3-18-1.

The biosynthetic pathway of eicosapentaenoic acid (EPA) has previously been reported in marine bacteria, while the regulatory mechanism remains poorly understood. In this study, a putative transcriptional regulator PfaR encoded adjacent to the PFA biosynthesis gene cluster () was computationally and experimentally characterized. Comparative analyses on the wild type (WT) strain, in-frame deletion, and overexpression mutants revealed that PfaR positively regulated EPA synthesis at low temperature.

An RpoN-dependent PEP-CTERM gene is involved in floc formation of an Aquincola tertiaricarbonis strain.

Background: The floc is a characteristic of microbial aggregate growth, displaying cloudy suspensions in water. Floc formation has been demonstrated in a series of bacteria and the floc-forming bacteria play a crucial role in activated sludge (AS) process widely used for municipal sewage and industrial wastewater treatment over a century. It has been demonstrated that some exopolysaccharide biosynthesis genes and the sigma factor (sigma54 or rpoN) were required for floc forming in some bacteria.

Sulfamethoxazole degradation by Pseudomonas silesiensis F6a isolated from bioelectrochemical technology-integrated constructed wetlands.

The antibiotic-degrading ability and mechanism of the bacteria in the novel and ecological bioelectrochemical technology-integrated constructed wetlands (BICW) remain unknown. In this study, the sulfamethoxazole (SMX) degrading strain Pseudomonas silesiensis F6a (F6a), which had high degradation efficiency, was firstly isolated from a substrate sample in BICW. The SMX degradation process of F6a follows pseudo first order kinetics.

Cellulose-mediated floc formation by the activated sludge bacterium Shinella zoogloeoides ATCC 19623.

Background: Bacterial floc formation plays a central role in the activated sludge (AS) process. The formation of AS flocs has long been known to require exopolysaccharide biosynthesis. We had demonstrated that both expolysaccharides and PEP-CTERM (a short C-terminal domain includes a near-invariant motif Pro-Glu-Pro (PEP)) proteins were required for floc-forming in Zoogloea resiniphila MMB, a dominant AS bacterium.

gen. nov., sp. nov., a novel member of family , isolated from a water purification facility with supplement of starch as a carbon source.

During a survey of microbial communities in the influent (ambient water) and effluent of a water purification facility with aeration and supplement of starch as carbon source, a novel bacterial strain, designated SZ9, was isolated from the effluent sample. Colonies of strain SZ9 were small (approximately 0.5-1.

Extracellular proteins of Desulfovibrio vulgaris as adsorbents and redox shuttles promote biomineralization of antimony.

Biomineralization is the key process governing the biogeochemical cycling of multivalent metals in the environment. Although some sulfate-reducing bacteria (SRB) are recently recognized to respire metal ions, the role of their extracellular proteins in the immobilization and redox transformation of antimony (Sb) remains elusive. Here, a model strain Desulfovibrio vulgaris Hildenborough (DvH) was used to study microbial extracellular proteins of functions and possible mechanisms in Sb(V) biomineralization.

Triclosan weakens the nitrification process of activated sludge and increases the risk of the spread of antibiotic resistance genes.

The usage of triclosan (TCS) may rise rapidly due to the COVID-19 pandemic. TCS usually sinks in the activated sludge. However, the effects of TCS in activated sludge remain largely unknown.

Carbon-negative and high-rate nutrient removal using mixotrophic microalgae.

Mixotrophic microalgae have demonstrated great potential for wastewater nutrient removal. How autotrophy/heterotrophy shares affect nutrient removal as well as carbon budget has not been understood. In this study, the autotrophy/heterotrophy shares in mixotrophy were quantified, and N removal rate and carbon budget under different mixotrophic autotrophy/heterotrophy shares were modeled.

Changes of microbial community structure during the initial stage of biological clogging in horizontal subsurface flow constructed wetlands.

The clogging is a universal problem in constructed wetlands, where microorganisms play an essential role. However, the implication of micro-organism variation due to the clogging is not clear. Four horizontal subsurface flow constructed wetlands (HFCWs) were designed and operated to simulate the process of clogging.

Tropical and temperate wastewater treatment plants assemble different and diverse microbiomes.

The diversity and assembly of activated sludge microbiomes play a key role in the performances of municipal wastewater treatment plants (WWTPs), which are the most widely applied biotechnological process systems. In this study, we investigated the microbiomes of municipal WWTPs in Bangkok, Wuhan, and Beijing that respectively represent tropical, subtropical, and temperate climate regions, and also explored how microbiomes assembled in these municipal WWTPs. Our results showed that the microbiomes from these municipal WWTPs were significantly different.

Dissimilatory Nitrate Reduction to Ammonium (DNRA) and Denitrification Pathways Are Leveraged by Cyclic AMP Receptor Protein (CRP) Paralogues Based on Electron Donor/Acceptor Limitation in Shewanella loihica PV-4.

Under anoxic conditions, many bacteria, including strain PV-4, could use nitrate as an electron acceptor for dissimilatory nitrate reduction to ammonium (DNRA) and/or denitrification. Previous and current studies have shown that DNRA is favored under higher ambient carbon-to-nitrogen (C/N) ratios, whereas denitrification is upregulated under lower C/N ratios, which is consistent with our bioenergetics calculations. Interestingly, computational analyses indicate that the common cyclic AMP receptor protein (designated CRP1) and its paralogue CRP2 might both be involved in the regulation of two competing dissimilatory nitrate reduction pathways, DNRA and denitrification, in PV-4 and several other denitrifying species.

sp. nov., a novel member of isolated from activated sludge collected in Hong Kong.

A floc-forming bacterial strain, designated HKLI-1, was isolated from the activated sludge of a municipal sewage treatment plant in Hong Kong SAR, PR China. Cells of this strain were Gram-stain-negative, strictly aerobic, catalase- and oxidase-positive, rod-shaped and motile by means of a single polar flagellum. Growth occurred at 18-37 °C (optimum, 28 °C), pH 5.

Gene expression abundance dictated exopolysaccharide modification in Rhizobium radiobacter SZ4S7S14 as the cell's response to salt stress.

A molecular and metabolic behaviour of EPS-producing and salt-tolerant bacterium Rhizobium radiobacter SZ4S7S14 along with its practical application in salt-stress was investigated. The research target was identification and expression profiles of a large EPS biosynthesis gene cluster, possible structural modification of EPS under salt-stress effect and analysis of the gene(s) relative expression and structural modification correlation. As expected, transposons insertions were identified within or near the coding regions of exoK and exoM, previously known large gene cluster that is required for EPS I synthesis.

Production of Highly Active Extracellular Amylase and Cellulase From ZIM3 and a Recombinant Strain With a Potential Application in Tobacco Fermentation.

In this study, a series of bacteria capable of degrading starch and cellulose were isolated from the aging flue-cured tobacco leaves. Remarkably, there was a thermophilic bacterium, ZIM3, that can simultaneously degrade both starch and cellulose at a wide range of temperature and pH values. Genome sequencing, comparative genomics analyses, and enzymatic activity assays showed that the ZIM3 strain expressed a variety of highly active plant biomass-degrading enzymes, such as the amylase AmyE1 and cellulase CelE1.