Asian Journal of Microbiology and Biotechnology
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Dual-fungal Bioconversion Model for Ethanol Production from Agro-waste Using Trichoderma viride and Aspergillus niger
No full textThe exponential generation of agro-industrial waste in India estimated at over 350 million metric tons annually poses a dual threat of environmental degradation and missed valorization opportunities. While rich in cellulose and hemicellulose, the complex lignocellulosic matrix of such biomass limits its direct fermentability. In this study, a decentralized, fungal-only bioconversion model is proposed for sustainable ethanol production using Trichoderma viride and Aspergillus niger, both isolated from pond and compost niches due to their adaptation to high organic stress environments. The biomass matrix comprising fruit pulp, sugarcane bagasse, and vegetable residues was pretreated via overnight soaking in 10% H₂SO₄ followed by a 5-minute steam explosion at 180 °C and 1.2 MPa, leading to effective delignification and the release of 42.6 g/L of fermentable sugars. Fungal enzymatic hydrolysis was enhanced by the addition of 0.5% carboxymethyl cellulose (CMC), which improved matrix loosening and enzyme substrate interaction. Fermentation was carried out by an ethanol-tolerant Saccharomyces cerevisiae strain, isolated from dried fig, under semi-anaerobic conditions at 32 °C. The process achieved a final ethanol yield of 10.6% (v/v), with a pH drop from 6.2 to 4.8 and refractive index stabilization at 1.341, confirming active fermentation. Viability tests revealed sustained fungal growth (2-1 × 10⁷ CFU/mL) after 30 days, confirming that the process is biologically stable and potentially reusable.
Comparative analysis against previous bacterial fungal systems showed that this dual-fungal consortium offers superior substrate adaptability, reduced contamination risk, and higher ethanol recovery from heterogeneous feedstock. The approach avoids commercial enzyme dependency and high-energy demands, offering a low-cost, modular strategy aligned with India’s bioenergy and circular economy goals. Although this study focused on ethanol generation, the fungal-rich residue presents additional potential for biofertilizer applications reserved for future work
Microbial Biomarkers for Soil Health Assessment: A Review of Current Approaches and Future Directions
No full textSoil health is fundamental to agricultural productivity, ecosystem stability, and climate resilience, yet traditional assessments based on physical and chemical properties fail to capture key biological processes. Microbial biomarkers encompassing taxonomic, functional, and metabolic indicators offer a transformative approach by linking microbial communities to soil functionality. This review synthesizes current knowledge on microbial biomarkers, evaluating their utility in assessing nutrient cycling, carbon dynamics, and stress responses. We systematically analyzed peer-reviewed studies (2010–2024) from major databases (Scopus, Web of Science), focusing on standardized methodologies, biomarker correlations with soil functions, and field applications. Key findings demonstrate that enzymatic biomarkers (e.g., β-glucosidase) strongly predict carbon turnover (explaining 62–85% of variability), while functional genes (nifH, phoD) outperform taxonomic data in forecasting crop yields and nutrient availability. However, challenges persist, including high spatial-temporal variability in microbial communities, methodological inconsistencies, and limited adoption in developing regions due to cost and expertise barriers. Emerging solutions include portable nano-sensors for real-time enzyme monitoring, AI-driven integration of multi-omics data, and CRISPR-based field tests. Future research must prioritize: (1) global standardization of protocols, (2) affordable tools for resource-limited settings, and (3) policy frameworks integrating microbial metrics into soil health indices (e.g., USDA Soil Health Index). The review conclude that microbial biomarkers are indispensable for advancing precision soil management, but their potential hinges on interdisciplinary collaboration and equitable technology access. By bridging lab-to-field gaps and fostering data-sharing initiatives, these tools can revolutionize sustainable land-use practices worldwide
Microbiological Air Quality and Antibiotic Resistance in Poultry Farms and Farmhouses
No full textInvestigating the microbial air quality of farms is very important for evaluating poultry\u27s impact on the area\u27s microbial air quality and the effects of human exposure to these emissions. The microbiological air quality of poultry farms, farmhouses, and their antibiogram were investigated to ascertain the air quality and antimicrobial resistance. The poultry farms assessed are in Ozuoba, Alcania, and Aluu in Obio-Akpor and Ikwerre Local Government Areas of Rivers State, Nigeria. The air microbial quality was determined using Koch’s sedimentation method by exposing sterile Nutrient agar, MacConkey agar, and Sabouraud dextrose agar plates one meter (1m) above ground level in the sites for the isolation of total heterotrophic bacteria, coliform, and fungi. Antibiotic susceptibility testing was done using the Kirby-Bauer disk diffusion technique with commercially available antibiotics. Total heterotrophic bacterial counts ranged from 2.31±0.21 to 4.31±0.63 log10Cfu/M3, total coliform counts ranged from 0.0 to 2.4±0.2 log10Cfu/M3 and fungal counts ranged from 1.9±0.1 to 2.9±0.31 log10Cfu/M3. Percentage occurrence of the bacterial isolates were Bacillus sp (18.9%), E. coli (21.1%), Salmonella spp. (13%), Enterobacter spp. (12.5), Klebsiella spp. (9.5%), Micrococcus spp. (6.3%), Serratia spp. (3.1%) and Staphylococcus sp (15.6%) were isolated from the farms. Results showed that E. coli was the most dominant bacterial isolate followed by Bacillus spp. While Serratia was the least occurring bacterial isolate. The percentage occurrence of fungal isolates was Candida sp (13.2), Mucor sp (10.5%), Cryptococcus sp (13.2%), Rhizopus sp (7.9%), Penicillium sp (13.2%), Aspergillus sp (23.7%), Fusarium sp (7.9 %) and Microsporum sp (10.5 %). The most dominant fungal isolates were the Aspergillus spp. A high resistance (80-100%) to Augmentin, ceftazidime, and cefuroxime was observed for the Gram-positive and negative isolates. Additionally, S. aureus, E. coli, Serratia, Klebsiella, and Micrococcus spp. exhibited multidrug resistance. High microbial populations and types were recorded in the pens than in the living houses. Proper waste handling, hygiene, use of PPEs, and awareness of drug use are recommended to curb health-related diseases due to exposure to microbial aerosols and reduce antimicrobial resistance
Bacteriological Assessment of Soils of Municipal Solid Waste Dumps of Choba, Rivers State
No full textThe study analysed the bacteria associated with the soils of solid waste dump sites in Choba, Rivers State. The total heterotrophic counts of the bacteria present in the soils of the dump sites, their frequencies of occurrence and their lipolytic, cellulolytic and proteolytic potentials were determined; the bacterial isolates that showed zones of inhibition were also screened for their antibacterial activity against Staphylococcus aureus and Escherichia coli. A total of four soil samples were collected from four different dump sites in Choba. The samples were serial diluted up to 10-4 and 0.1ml spread on nutrient agar plates. The total heterotrophic bacteria counts for samples A, B, C and D were 2.8×106 cfu/g, 2.0 × 107 cfu/g, 4.3 × 106 cfu/g and 1.5 × 107 cfu/g respectively. The bacteria isolated with their frequencies of isolation were: Salmonella typhi (75%), Pseudomonas aeruginosa (50%), Shigella flexneri (25%), Escherichia coli (25%), Arthrobacter (50%), Klebsiella (25%), Acinetobacter (25%), Enterobacter (50%), Micrococcus (25%), Citrobacter (25%), Enterococcus faecalis (50%), Bacillus subtilis (25%), Staphylococcus (50%), and Serratia marcescens (50%). Salmonella typhi had the highest frequency of occurrence, being present in three soil samples. The cellulolytic, proteolytic and lipolytic potentials of the isolates were determined using appropriate media. Only Pseudomonas aeruginosa, Acinetobacter, Bacillus subtilis and Serratia marcescens tested positive to cellulose, protein and lipid hydrolysis. Bacillus subtilis exhibited antimicrobial activity during isolation and was tested against E. coli and S. aureus. The zones of inhibition observed against E. coli and S. aureus were 10mm and 15mm respectively. From the results of the analysis, it can be observed that large numbers of diverse species of bacteria are present in dump sites. The presence of pathogenic bacteria in these dump sites has made it imperative that measures be put in place to curtail the potential health hazards that these pathogens can cause
Phytochemical Composition and Health Benefits of Mulberry Plant Parts: A Review
No full textMulberry (Morus spp.), a traditional medicinal and nutritional plant, has been widely investigated for its bioactive composition and associated health benefits. Different parts of the mulberry plant, including leaves, fruits, bark, and roots, are rich in phytochemicals such as flavonoids, polyphenols, alkaloids, anthocyanins, stilbenes, and polysaccharides. Leaves are particularly abundant in 1-deoxynojirimycin (DNJ), flavonoids, and phenolic acids, which contribute to their antidiabetic, hypolipidemic, and hepatoprotective properties. Fruits are notable for anthocyanins, resveratrol, and vitamins that exhibit antioxidant, anti-inflammatory, and neuroprotective effects, while also supporting cardiovascular health. The root bark contains stilbenes and prenylated flavonoids with antimicrobial, anticancer, and anti-obesity potential. Moreover, mulberry extracts demonstrate immunomodulatory, anti-aging, and neuroprotective activities, validating their role in both preventive and therapeutic applications. Current evidence from in vitro, in vivo, and limited clinical studies supports the safety and efficacy of mulberry-derived products in promoting human health, though standardization of bioactive compounds and long-term safety evaluations remain necessary. This review highlights the compositional diversity of mulberry plant parts and their pharmacological significance, providing a basis for future nutraceutical and pharmaceutical developments
Prevalence and Antimicrobial Resistance of Enterohemorrhagic Escherichia coli (Ecoli.0157) in Children under Five Years Old with Diarrhea at Enugu State University Teaching Hospital (ESUT)
No full textEscherichia coli (E. coli) is a leading cause of diarrhoea in low- and middle-income nations, particularly among children under the age of five. This study aimed to determine the prevalence of Enterohemorrhagic E coli (E coli 0157) and the antimicrobial susceptibility in children less than five years old in Enugu State University of Science and Technology Teaching Hospital. The study employed a mixed cross-sectional design which was carried out from October-November 2024 Esuth Teaching Hospital. Ethical considerations were met before 83 stool samples were collected from eligible children, and questionnaires administered. Samples were cultured on Coliform chromogenic (E coli 0157) agar and antimicrobial susceptibility testing were done using the Kirby- Bauer Disk Diffusion Method. The findings revealed a prevalence of 15 out of 83 participants (18%) for E. coli O157, with a slightly higher prevalence in females (21%) than males (15%). The most affected age group was children aged 1-2 years (46.7%). Vomiting was reported in 57% of cases, fever in 23%, abdominal pain in 64%, and dehydration in 58%, with 85.5% presenting loose or watery stools and semi-formed stools (14.5%). Antimicrobial susceptibility testing indicated that while several strains were sensitive to antibiotics there was significant resistance to some. The study found an 18% prevalence of E. coli O157 in children under 5 in Enugu, Nigeria, with higher rates in females and the 1-2 age group. Also susceptibility studies showed significant rate of resistance in amoxicillin, nitrofurantoin and streptomycin drugs. Poor sanitation and hygiene were linked to infections. Antimicrobial resistance was also shown to be prevalent. The outcome of the study indicate a key relationship between sex and prevalence of the disease as well as the relative epidemiological predispositions. In conclusion, the study underscores the urgent need for improved public health initiatives focused on sanitation and hygiene practices to mitigate E. coli infections, alongside continuous monitoring of antimicrobial resistance patterns to inform treatment protocols
Evaluation of Rhizobacteria and Siderophores-Producing Bacteria from Roots of Selected Leguminous Crops
No full textSiderophore production is a potential tool for plant growth promotion and biocontrol. This study evaluated rhizobacteria and siderophore-producing bacteria obtained from roots of leguminous crops. Soil sample were obtained from root regions of common beans (Phaseolus vulgaris L.), peanut (Arachis hypogaea L.), soybeans [Glycine max (L.) Merr.], and cowpea [Vigna unguiculata (L.) Walp.]. Bacterial isolates were identified based on their morphological and biochemical characteristics. Results obtained were compared with those of Bergey\u27s manual of Systematic Bacteriology. All bacteria were screened for ability to produce indole acetic acid (IAA), ammonia, and phosphate solubilisation, using qualitatively methods. Siderophore production and types of siderophore were determined by growing all organisms on enriched Chrome Azurol S (CAS) agar/broth. The findings revealed the presence of twenty-three (23) bacteria belonging to eight (8) genera that include; Bacillus, Corynebacterium, Enterococcus, Micrococcus, Proteus, Pseudomonas, Staphylococcus, and Streptococcus. All bacteria produced IAA except Enterococcus sp. (BPV) while all bacteria produced ammonia except Bacillus sp. (PAH), Bacillus subtilis (CVU), Enterococcus sp. (BPV), and Staphylococcus sp. (PAH). Bacillus subtilis (SGM), Bacillus sp. (PAH), Enterococcus sp (BPV), Proteus sp. (SGM), Staphylococcus saprophyticus (SGM), and Streptococcus (PAH) were among six bacteria that could not solubilize phosphate. Also, most of the organisms were siderophore-producing bacteria with Bacillus and Pseudomonas genera producing the strongest siderophores, which varied from carboxylate, hydroxamate to catecholate-type siderophores. The use of rhizobacteria and siderophore-producing bacteria (SPB) should be encouraged to improve environmentally friendly farming system and ensure food safety
Exploring the Potential of Bacteria Isolated from Damp Yard Leachate for Lignocellulose Biodegradation
No full textThe accumulation of lignocellulosic waste, particularly from agro-industrial sources such as coconut coir fibre, poses a significant environmental challenge due to its recalcitrant nature and resistance to natural decomposition. This study explores the potential of bacterial isolates from damp yard leachate for the biodegradation of lignocellulose in coconut coir fibre. Twenty-four bacterial strains were isolated from Perungudi municipal damp yard and screened for lignolytic and cellulolytic activities using alkaline lignin and carboxymethyl cellulose substrates. Among these, members of the genera Bacillus, Pseudomonas, and Aneurinibacillus were predominant, with eight isolates demonstrating substantial enzymatic activity. These efficient strains were combined to form a microbial consortium for solid-state fermentation of coir fibre over 30 days. Fourier transform infrared spectroscopy (FTIR) analysis revealed significant structural changes in functional groups associated with lignin and cellulose corresponding to approximately 35% lignin degradation and 45% cellulose degradation, confirming effective biodegradation. A pot study using the degraded substrate, with and without microbial inoculation and vermicompost, evaluated its effect on fenugreek (Trigonella foenum-graecum) growth. Results indicated that plant growth was enhanced when the degraded substrate was combined with vermicompost, suggesting that nutrient supplementation is essential for agricultural applications. Overall, the study highlights the biodegradation potential of damp yard-adapted microbes and supports their application in sustainable waste management strategies. These findings offer a promising biological alternative to conventional lignocellulose treatment methods and demonstrate potential in producing value-added biofertilizer from agro-waste
Isolation and Characterization of Canine-specific Lactic Acid Bacteria from Fecal and Oral Samples of Dogs
No full textLactic acid bacteria constitute a major group of probiotic bacteria to be used as probiotic supplement for animals. The lactic acid bacteria are always species specific, but none of the commercial probiotic product of dogs are of canine origin. The isolation and characterization of lactic acid bacteria from canine fecal samples are important for preparation of species specific probiotic supplement. A total 160 numbers of Canine oral and fecal lactic acid bacteria Strains were isolated from 60 healthy dogs. Lactic Acid Bacteria were found in 37% of canine fecal samples and 9 % of canine oral samples. Then these samples were cultivated on lactobacillus selective media with acetic acid. The pro-biotic strains analysed based on the frequency and quantity in feces, growth density, acid tolerance antimicrobial activity, biochemical test and antibiotic sensitivity test. Among 160 fresh oral and fecal samples, 60 fecal samples and 15 oral samples were showed positive for lactic acid bacteria grown in lactobacillus selective media MRS broth and Rogosa agar. The 160 CFU / ml of culture were obtained by spread plate technique by using fresh fecal samples of healthy dogs but 10 CFU/ml obtained dogs which as having enteritis. The broad spectrum group of antibiotic used to check the antibiotic susceptibility and few of commonly used antibiotic have maximum zone of inhibition in probiotic culture. The isolates shows positive for catalase test, nitrate reduction test, citrate test. The lactic acid bacteria strain present in oral and fecal samples were identified by partial 16s rRNA gene sequencing of a fragment amplifier by PCR using universal primer. 900bp PCR product was obtained in 1% agarose gel. Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus casei, Lactobacillus mucosae, Lactobacillus delbrueckii and Lactobacillus salivarius were most frequently encountered bacteria in canine oral cavity and feces. Sequence similarity values of 93 % with Lactobacillus casei, 89% with Lactobacillus pentosus, 85% with Lactobacillus delbrueckii were found
Biomarkers for Tuberculosis Diagnosis and Monitoring: A Review of Translational Progress
No full textTuberculosis (TB) still presents a major threat to public health, and accurate diagnosis of tuberculosis, monitoring TB treatment, as well as TB drug resistance are still challenging goals. Research in biomarkers—both host, pathogen pathogen-derived—has led to novel frontiers in the diagnosis and management of TB. These advancements contribute to faster diagnosis, customized treatment plans, and better monitoring of response to therapy. Direct pathogen-based markers, such as M. tuberculosis DNA, lipoarabinomannan (LAM), and mycobacterial proteins, that directly demonstrate infection, have the most potential, particularly in resource-poor settings. Cytokines such as interferon-gamma (IFN-γ) and inflammatory markers, such as C-reactive protein (CRP), are endogenous biomarkers that mirror responses of the immune system and may play a role in the management of treatment, especially in immunocompromised populations, such as patients with HIV. These progresses notwithstanding, the application of a biomarker-centered approach on a large scale remains a major obstacle, due to technical, economic, and regulatory constraints. Furthermore, various performances among the biomarkers in different populations limit clinical utility. Future studies in this area should aim to create point-of-care diagnostics, multi-biomarker panels, and to integrate the device with digital health technology platforms for real-time monitoring. These methods have the potential to substantially improve TB control, particularly in low- and middle-income countries. If current challenges can be overcome and research horizons broadened, biomarker-driven diagnosis and monitoring strategies may have key contributions in global TB control