Indian Journal of Microbiology最新文献

Non-typhoidal Salmonella (NTS) infections have gained global scientific attention due to the wide spectrum of illnesses they cause and associated treatment challenges. Antimicrobial therapy is critical for severe NTS infections, but the emergence of resistant strains raises concerns for public health authorities. This study focuses on the isolation of an extremely drug-resistant NTS serovar, Salmonella enterica serovar Weltevreden (S. Weltevreden), in India. The serovar was subjected to comprehensive biotyping, serotyping, antibiogram profiling, and ESBL production. The presence of bla _CTX-M-15, bla _TEM, bla _SHV, and bla _CMY-2 genes was also investigated in the isolate. The serovar was further tested for biofilm and colicin production. The findings revealed a high level of antimicrobial resistance exhibiting resistance to 16 out of the total 20 tested antimicrobial drugs viz. ampicillin, amikacin, ciprofloxacin, cotrimoxazole, cefepime, ceftriaxone, ceftazidime, cefotaxime, cefuroxime, gentamicin, kanamycin, meropenem, nalidixic acid, nitrofurantoin, norfloxacin, trimethoprim. The serovar was also found to be an ESBL producer, harboring the bla _CTX-M-15 and bla _CMY-2 genes. Biofilm and colicin production were also detected in the serovar. These findings point towards the extent of drug resistance present in the NTS serovar and the need for urgent attention from the public health authorities. Although, this study reports a single case of extensively drug-resistant NTS serovar, the possibility of more such serovars circulating in the community cannot be ruled out. Hence, there is an urgent need to implement effective antibiogram surveillance among NTS to detect such serovars and to formulate effective policies regarding antibiotic usage.

Fungal biotransformation is a relevant strategy to obtain high-added value natural compounds under controlled environmentally friendly conditions. R-(+)-limonene is the main component of the orange peel oil, which is available in large amounts, at low cost, and can be employed in biotransformation processes as a precursor of different value-added aroma compounds. The goal of the study was to evaluate the ability of filamentous fungi from the Brazilian Amazon to biotransform R-(+)-limonene. The fungal biotransformation assays were executed using forty-seven filamentous fungi and executed in flasks containing the substrate R-(+)-limonene in mineral medium for 120 h. In this study, nine endophytic fungi, two macrofungi, and one aquatic fungus were considered potential candidates for limonene biotransformation, since they eventually accumulated interesting compounds after 120 h of reaction. However, only Pestalotiopsis mangiferae LaBMicrA-505 was the most promising endophytic fungi found in the screening, due to its capacity to use all the R-(+)-limonene as the single carbon and energy source in a mineral medium, with the main oxygenated derivatives being limonene-1,2-diol (74.13 ± 0.81%) and limonene-1,2-epoxide (1.88 ± 0.08%), which were accumulated after 72 h of reaction. These achievements are important and support the development of the production of natural aromas and demonstrate the potential of using these wild Amazonian fungi as new biocatalysts.

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Supplementary information: The online version contains supplementary material available at 10.1007/s12088-024-01428-x.

The present study aimed at developing a bacterial consortium for enhanced growth, yield and nutrient content of rapeseed-mustard. Fifty morphologically distinct bacteria were obtained from leaves, stem, roots and rhizosphere of rapeseed-mustard collected from Punjab, India exhibited phosphate solubilization ranging from 20.6 to 160.6 μg/ml in liquid medium. Thirty-one isolates showed zinc solubilization and siderophore production. All the isolates were positive for auxin and ammonia production but negative for hydrogen cyanide production. Fourteen isolates were able to exhibit luxuriant growth on three media without any nitrogen source. The bacterial treatments in pots showed significant improvement in plant growth, chlorophyll content, and nitrogen, phosphorus, and potassium contents in both plants and soil compared to the control treatment. Two isolates showing the highest growth-promoting activity were identified as Pseudomonas putida MLE8 and Serratia proteamaculans MRE2 by MALDI-TOF-MS and 16S rRNA gene sequencing. The consortium of P. putida MLE8 and S. proteamaculans MRE2 (PpMLE8 + SpMRE2) improved the growth, yield attributes, oil content, yield, shoot nutrient content and available N, P and K content of soil in the fields of B. juncea var. PBR 357 during 2020-21 and B. napus var. GSC 6 during 2021-22. The application of bacterial consortium with 100% RDF improved the seed and oil yield of Brassica napus var. GSC 7 by 11.8% and 12%, respectively, during 2022-23 and seed yield by 6.4% during 2023-24 with increased mean net returns by Rs 13,137/ha and B:C ratio by 0.28 in comparison to uninoculated control treatment.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-024-01443-y.

The Zika virus and its deadly infectious status is a major concern to the world and the scientific community is trying to tackle the problem. The variability in the genomic material of the various isolates from different geographical locations put forward a major hurdle in designing effective therapeutics against the evolving strains. The time and resources utilized for the therapeutic development against this virus and its efficacy against viral infection inhibition are also concerning. Therefore, in the present study we have opted for a computational approach to first identify the significant markers within the genomes of ZV from India, Africa, and South America origin and employ relative synonymous codon usage and host adaptation-based approaches. The homology observed between these strains in their envelope protein suggests this protein can be utilized for vaccine development upon in vitro validations.

Despite the availability of numerous efficient conventional wastewater treatment technologies, over 80 percent of all wastewater produced is discharged into aquatic bodies worldwide without adequate treatment. Traditional wastewater treatment methods are expensive, technologically complex, and energy-intensive; thus, it becomes imperative to explore nature-based solutions that are sustainable and economical. Constructed wetlands (CWs) are ecologically engineered and self-adaptive wastewater treatment and management systems designed to employ the processes taking place in a natural wetland with a greater degree of control. Microbes play a key role in transforming and mineralizing pollutants in CW. Nitrosomonas, Nitrosospira, Proteobacteria, Actinobacteria, Firmicutes, Chloroflexi, and Bacteroidetes are some of the commonly reported species in wetland systems. Microbes metabolize nutrients and organic pollutants through various processes like nitrification, denitrification, sulfate reduction, and methanogenesis. Bioaugmentation and the incorporation of various other innovative approaches to improve the efficiency and long-term performance of constructed wetlands has received a lot of attention lately. The present work attempts to review the role of microbes in CWs and the influence of microbial augmentation on the performance enhancement of wetland systems. Additionally, the influence of selecting appropriate components (substrate and plants) for the wetland system; optimizing crucial design elements (wetland configuration, loading rate, retention time, flow pattern), and adopting other innovative approaches (like vermifiltration, effluent recirculation, aeration, and integration of microbial fuel cell) on the treatment of constructed wetland system is also reviewed. The stability, sustainability, and implementation of constructed wetland systems can be significantly enhanced by incorporating performance enhancement approaches.

The generation of wastewater has surpassed the capacity of existing conventional treatment methods, creating a significant gap that requires immediate attention. The need for ecologically and economically effective decentralized wastewater treatment approaches has become increasingly apparent, especially in regions lacking resources and infrastructure. A promising solution to bridge the gap in wastewater treatment capacity is the use of natural and constructed wetlands that leverage the ability of plants and microbes to remediate contaminated water while providing sustainable solutions to address the global water crisis. The use of wetland systems presents an opportunity to sustainably manage wastewater through cost-effective and environmentally friendly means. Microorganisms play a pivotal role in these wetland systems by supporting plant growth, catalyzing chemical reactions and processes like biodegradation, bioaccumulation, and biosorption, etc. Understanding the roles of microbial communities in wetlands and their impact on pollutant removal can provide valuable insights for enhancing the treatment efficiency of wetlands. To explore functional microbial communities in these systems, a bibliometric analysis using the keywords "Wetland" and "Microorganisms" in the "Title" was performed to evaluate recent research trends and answer pertinent research questions. Proteobacteria , Bacteroidetes , Actinobacteria, and Firmicutes were most abundant phylum discovered in wetlands. These organisms facilitate the transformation and mineralization of pollutants by metabolizing nutrients and organic pollutants through various processes such as nitrification, denitrification, sulfate reduction, and methanogenesis, etc. The analysis indicates the importance of further research in exploring functional microorganisms, microbial community dynamics, and their interaction with plants and other wetland components.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-025-01496-7.

Hot springs naturally produce geothermally heated water and are renowned for their diverse microbial communities. Metagenomics studies unveil this microbial diversity. In this study, the bacterial community, along with thermophilic actinobacteria from the Rajgir hot spring, located in Bihar, India, was analyzed using 16S rRNA gene metagenomics sequencing. The sediment temperature was recorded at 45 °C. Investigation of the hot spring ecology revealed the presence of 16 bacterial phyla, with actinobacteria being abundant. Streptomyces, Sphingomonas, Gemmatimonas, Paracoccus, Aeromicrobium, and Actinomyces were among the most common genera found in the sediment samples. These six genera exhibited the highest abundance, with Streptomyces being the most prevalent at 19%, followed by other genera at 13%, 11%, 11%, 10%, and 9%, respectively. Actinobacteria isolated from the hot spring samples were further examined for their antibacterial activities against pathogenic bacteria. Isolates from the Rajgir hot spring demonstrated potential antibacterial activity based on their inhibition zones on agar plates. The results of the antimicrobial screening revealed that AIBRSS1 exhibited the most significant inhibition zone, measuring 26 mm, against Listeria monocytogenes.

Supplementary information: The online version contains supplementary material available at 10.1007/s12088-025-01482-z.

The global demand for sustainable waste management solutions has driven significant interest in the bioprocessing of agri-food waste. Microbial bioprocessing offers a transformative approach to their valorisation, promoting a sustainable circular economy. This article explores the shifting paradigm in waste management strategies, emphasizing the potential of microbial bioprocessing to transform organic residues into valuable products. We discuss the challenges and limitations associated with microbial bioprocessing, including feedstock complexity, process optimization, microbial strain performance and regulatory considerations. Further, we highlight innovative solutions such as strain engineering, co-culture approaches, and biorefinery concepts that enhance process efficiency and product diversification. Through the integration of biorefinery concepts and circular economy models, microbial bioprocessing offers a promising pathway toward resource conservation, environmental sustainability, and economic prosperity.

The plant rhizosphere harbors various kinds of microbes that play significant roles in plant growth. Sulfur oxidizing bacteria (SOB) play a vital role in the oxidation of elemental sulfur to plant accessible sulfate, which helps in plant growth, acts as a biocontrol, and acts as a bioleaching agent. In our present work, we explored the diversity of sulfur oxidizing bacteria from the rhizosphere of Catharanthus, Begonia, Pisum, Trigonella, Spinacia and Azadirachta. Twenty five bacterial strains were isolated and stabbed in thiosulfate containing growth medium. Out of twenty five isolates, six most effective strains, CR1, PS2, SO3, TF4, BS5 and AI6 with a remarkable change in color of the thiosulfate containing growth medium from red to yellow due to sulfate production, were selected for plant growth promoting activities such as phosphate solubilization, IAA production, HCN and ammonia production. All six bacterial strains showed significant Plant Growth Promoting Rhizobial (PGPR) activities with the production of indole-3-acetic acid (662 to 724 μg ml^-1) and phosphate solubilization (7 to 14 μg ml^-1). Selected strains and their consortium are further assessed for growth responses on Vigna radiata L. under in-vitro conditions. Based on the analysis of variances, seed priming with different sulfur oxidizing bacterial strains showed a significant (P < 0.05) effect on vigor index. The vigor index increased in primed as compared to unprimed seeds of Vigna radiata L. The maximum growth rate of seedlings for the single culture of CR1 (10.80) and for the mixed culture of CR1 + BS5 (10.94) was observed as compared to the control. All six SOB strains showed in-vitro plant growth promoting activities and may be used as a viable alternative to organic fertilizers and as potential applicants for sustainable agriculture.