Applied and Environmental Microbiology This is an RSS file. You can use it to subscribe to this data in your favourite RSS reader or to display this data on your own website or blog.

Accounting for the microbial assembly of each process in wastewater treatment plants (WWTPs): study of four WWTPs receiving similar influent streams
This study provided a novel concept that microorganisms follow a niche assembly in the activated sludge (AS) tank and that the AS contributed more than the sand filtration process toward the final microbial signature that is unique to each treatment plant. This observation highlights the importance of understanding the microbial community selected by the AS stage, which could contribute toward source-tracking the effluent from different wastewater treatment plants.PMID:38440988 | DOI:10.1128/aem.02253-23 (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - March 5, 2024 Category: Microbiology Authors: Hong Cheng Mohammad K Monjed Yevhen Myshkevych Tiannyu Wang Pei-Ying Hong Source Type: research

The S-S bridge mutation between the A2 and A4 loops (T416C-I432C) of Cel7A of Aspergillus fumigatus enhances catalytic activity and thermostability
In this report, cysteine residues are introduced to form disulfide bonds in the Glycoside Hydrolase family GH 7 cellobiohydrolase (GH7 CBHs) or Cel7A of Aspergillus fumigatus. Disulfide by Design 2.0 (DbD2), an online tool is used for the detection of the mutation sites. Mutations are created (D276C-G279C; DSB1, D322C-G327C; DSB2, T416C-I432C; DSB3, G460C-S465C; DSB4) inside and outside of the peripheral loops but, not in the catalytic region. The introduction of cysteine in the A2 and A4 loop of DSB3 mutant showed higher thermostability (70% activity at 70°C), higher substrate affinity (Km = 0.081 mM) and higher catalyti...
Source: Applied and Environmental Microbiology - March 5, 2024 Category: Microbiology Authors: Subba Reddy Dodda Musaddique Hossain Sudipa Mondal Shalini Das Sneha Khator Jain Kaustav Aikat Sudit S Mukhopadhyay Source Type: research

Investigating the association between nitrate dosing and nitrite generation by the human oral microbiota in continuous culture
Appl Environ Microbiol. 2024 Mar 5:e0203523. doi: 10.1128/aem.02035-23. Online ahead of print.ABSTRACTThe generation of nitrite by the oral microbiota is believed to contribute to healthy cardiovascular function, with oral nitrate reduction to nitrite associated with systemic blood pressure regulation. There is the potential to manipulate the composition or activities of the oral microbiota to a higher nitrate-reducing state through nitrate supplementation. The current study examined microbial community composition and enzymatic responses to nitrate supplementation in sessile oral microbiota grown in continuous culture. Ni...
Source: Applied and Environmental Microbiology - March 5, 2024 Category: Microbiology Authors: Thomas Willmott Hannah J Serrage Elizabeth C Cottrell Gavin J Humphreys Jenny Myers Paul M Campbell Andrew J McBain Source Type: research

Identification and characterization of the TetR family transcriptional regulator NffT in Rhizobium johnstonii 
In this study, we discovered the TetR-type regulator NffT, which suppressed the expression of fixA in Rhizobium johnstonii. Furthermore, NffT was confirmed to play pleiotropic roles in R. johnstonii-Pisum sativum symbiosis; specifically, it inhibited rhizobial growth, nodule differentiation, and nitrogen-fixing reactions. We revealed that NffT indirectly affected R. johnstonii-P. sativum symbiosis by participating in a complex regulatory network of symbiotic and carbohydrate metabolic genes. Furthermore, cobalamin, a chemical molecule, was reported for the first time to be involved in TetR-type protein transcription during...
Source: Applied and Environmental Microbiology - March 1, 2024 Category: Microbiology Authors: Xiaofang Li Zhangqun Li Yajuan Wei Zirui Chen Shijie Xie Source Type: research

Regulatory functions of homeobox domain transcription factors in fungi
Appl Environ Microbiol. 2024 Feb 29:e0220823. doi: 10.1128/aem.02208-23. Online ahead of print.ABSTRACTHomeobox domain (HD) proteins present a crucial involvement in morphological differentiation and other functions in eukaryotes. Most HD genes encode transcription factors (TFs) that orchestrate a regulatory role in cellular and developmental decisions. In fungi, multiple studies have increased our understanding of these important HD regulators in recent years. These reports have revealed their role in fungal development, both sexual and asexual, as well as their importance in governing other biological processes in these ...
Source: Applied and Environmental Microbiology - February 29, 2024 Category: Microbiology Authors: A M Calvo A Dabholkar E M Wyman J M Lohmar J W Cary Source Type: research

Progress on network modeling and analysis of gut microecology: a review
Appl Environ Microbiol. 2024 Feb 28:e0009224. doi: 10.1128/aem.00092-24. Online ahead of print.ABSTRACTThe gut microecological network is a complex microbial community within the human body that plays a key role in linking dietary nutrition and host physiology. To understand the complex relationships among microbes and their functions within this community, network analysis has emerged as a powerful tool. By representing the interactions between microbes and their associated omics data as a network, we can gain a comprehensive understanding of the ecological mechanisms that drive the human gut microbiota. In addition, the ...
Source: Applied and Environmental Microbiology - February 28, 2024 Category: Microbiology Authors: Meng Luo Jinlin Zhu Jiajia Jia Hao Zhang Jianxin Zhao Source Type: research

A multifunctional flavoprotein monooxygenase HspB for hydroxylation and C-C cleavage of 6-hydroxy-3-succinoyl-pyridine
This study highlights a key enzyme, HspB (6-hydroxy-3-succinoyl-pyridine monooxygenase), in breaking down nicotine through the pyrrolidine pathway. Utilizing dioxygen and a flavin adenine dinucleotide cofactor, HspB hydroxylates and cleaves the substrate's side chain. Structural analysis of the refined HspB crystal structure, combined with state-of-the-art computations, reveals its distinctive mechanism. The crucial function of Cys218 was never discovered in its homologous enzymes. Our findings not only deepen our understanding of bacterial nicotine degradation but also open avenues for applications in both environmental c...
Source: Applied and Environmental Microbiology - February 28, 2024 Category: Microbiology Authors: Xingyu Ouyang Gongquan Liu Lihua Guo Geng Wu Ping Xu Yi-Lei Zhao Hongzhi Tang Source Type: research

An atypical 3-ketoacyl ACP synthase III required for acyl homoserine lactone synthesis in Pseudomonas syringae pv. syringae B728a
We report that PssFabH1 and PssFabH2 each encode a 3-ketoacyl-acyl carrier protein synthase (KAS) III in P. syringae B728a. Whereas PssFabH2 is able to function in redirecting intermediates from β-oxidation to fatty acid synthesis, PssFabH1 is an atypical KAS III protein that represents a new KAS III clade based on its sequence, non-involvement in cell growth, and novel role in AHL synthesis.PMID:38415624 | DOI:10.1128/aem.02256-23 (Source: Applied and Environmental Microbiology)
Source: Applied and Environmental Microbiology - February 28, 2024 Category: Microbiology Authors: Qiaoqiao Guo Jingtong Su Yuling Liao Yin Yu Lizhen Luo Xiaoshan Weng Wenbin Zhang Zhe Hu Haihong Wang Gwyn A Beattie Jincheng Ma Source Type: research