Microbiology and Biotechnology Research: An Overview Vol. 7

A Comprehensive Review of Physiological, Morphological, and Agronomic Perspectives on Conventional Trait-based Approaches for Enhancing Drought Resistance in Wheat (Triticum aestivum L.)

2026-04-17T10:29:53+00:00

Wheat (Triticum aestivum L.) serves as a fundamental component of global food security; however, its production faces growing challenges due to frequent droughts intensified by climate change. The unpredictable rainfall, elevated temperatures, and heightened evapotranspiration have substantially undermined yield stability, jeopardising advancements in global food systems. Drought episodes have intensified worldwide due to climate variability, resulting in significant losses in wheat-producing areas. This review consolidates existing knowledge regarding traditional and trait-based methods for improving drought tolerance in wheat, emphasising physiological, morphological, and agronomic traits. The review also examines the intricacies of breeding for drought tolerance, emphasising challenges including genotype-by-environment interactions and the trade-offs between drought resistance and yield potential. Drought stress markedly diminishes wheat yield by adversely affecting plant height, tillering, spikelet count, and grain size, with the most pronounced losses observed during reproductive stages. Essential characteristics that enhance drought resilience encompass strong root architecture, a stay-green phenotype, osmotic adjustment, and increased water-use efficiency. Recent advancements in precision breeding, such as marker-assisted selection, genomic selection, and gene editing techniques like CRISPR/Cas9, are expediting the creation of drought-tolerant cultivars. Additionally, agronomic management practices are equally essential in mitigating drought effects. Integrated agronomic practices, climate-smart agriculture, and international collaborations are essential strategies for maintaining wheat productivity in water-limited environments. The review concludes that a multifaceted approach, integrating conventional breeding, biotechnological innovations, and adaptive management, is essential for ensuring yield stability and food security amid increasing climatic variability. Despite recent advances in scientific studies, numerous gaps persist in understanding genetic, physiological, and morphological determinants of drought tolerance that necessitate coordinated efforts from both scholars and policymakers to resolve.

Antimicrobial Activity and In-silico Molecular Docking Analysis of Azadirachta indica (Neem) Leaf Extracts against Multidrug-Resistant Clinical Isolates

2026-04-17T10:33:58+00:00

Azadirachta indica (neem) is widely recognised for its medicinal properties and extensive use in traditional medicine. The emergence of multidrug resistance and glucose 6 phosphate dehydrogenase deficiency resulting from infections and the use of synthetic pharmaceutical products for the treatment of infections has become a major public health threat. This study was designed to determine the antimicrobial effect of Azadirachta indica extracts in the context of G6PD deficiency and malaria co-infection on clinical isolates, comprising five (5) bacteria and four (4) fungi, using the agar well diffusion method. Minimum inhibitory and bactericidal concentrations, including kinetic growth of the isolates, were determined by macrodilution and spectrophotometry methods. The phytochemical and functional group profiling in the extracts was performed using GC–MS standard method and Fourier-Transform Infrared (FTIR) spectrophotometry. In-silico molecular docking analysis of the bioactive compounds in neem extract and oil was determined by computational modelling tools and the molecular Auto Dock software. Data were analysed using one-way ANOVA to compare the mean levels of significance of the parameters, where the level of significance was set as (P<0.05), and Duncan Multiple Range Test (DMRT) was used to compare the significance between the groups. The results revealed that aqueous neem extract exhibited limited antimicrobial activity, whereas methanolic and oil extracts demonstrated broad-spectrum antimicrobial potential. The aqueous extract produced the highest inhibition zone of 14 mm against Escherichia coli. Neem extracts demonstrate broad antifungal potential over amphotericin B, while methanolic neem has a 0.60 mm wide inhibitory zone against Saccharomyces cerevisiae. The minimum inhibitory concentration and minimum bactericidal concentration for neem oil were 2.00 mg/ml stronger. Growth kinetics indicated bacteriostatic effects of neem extracts on Staphylococcus aureus, Escherichia coli, Candida albicans, and Aspergillus niger. Neem oil and powder contain 14 and 18 phytochemical profiles, while α-D-Glucopyranose and n-Hexadecanoic acid were identified at the highest peak area of 21.98% and 12.31%, respectively. In-silico molecular docking identified diethylphthalate as a strong microbial protein inhibitor at -8.5 kcal, low binding energy with S aureus 1txt and E. coli 2ZIP proteins, while 9,17-octadecadienal (Z), methyl 10-methyl hexadecanoate, and oleic acid contributed to neem oil’s antibacterial activity with low binding energy of -8.00 kcal with S aureus 1txt and E. coli 2ZIP proteins. However, the therapeutic importance of neem in combating pathogenic microbes and its sustainability as an alternative medicine are significant. The findings of this research acknowledge and scientifically validate the use of plants against microbial pathogenic activities. The study recommends that plant extracts should be standardised by appropriate regulatory bodies to ensure their safe use, proper preservation, and sustainable utilisation, particularly in the context of the global prevalence of multidrug-resistant pathogens.

Relative Synonymous Codon Usage, Molecular Weight and Isoelectric Point Analysis of Cytokinin Gene Sequences in the Wheat (Triticum aestivum L.) Genome

2026-04-17T10:38:31+00:00

Cytokinins play an important role in plants and are targets of wheat breeding, particularly in terms of flowering and yield. The cytokinin expression of the Triticum aestivum through the amino acid is crucial for its development. This plant hormone plays a dual role in plant physiology, regulating both growth and stress adaptation. Only a few studies have integrated relative synonymous codon usage with protein physicochemical profiling for wheat cytokinin genes. Therefore, the objective of this study was to determine relative synonymous codon usage (RSCU), molecular weight (g mol⁻¹), theoretical isoelectric point, instability index, aliphatic index, and hydrophobicity for the wheat cytokinin sequences from two different databases. RSCU values were calculated as the ratio of the observed frequency to the expected frequency for the particular codon. The theoretical isoelectric point was calculated based on the dissociation constant for groups of carboxylic acid and amino acid groups. Principal component analysis (PCA) of RSCU values, molecular weight, and pI was performed using ExPASy tools and SAS 9.4. The results showed that values of the relative synonymous codon usage divided the amino acids of wheat into two groups. In the first group, values were above 1.6 (significant overrepresentation), such as those for phenylalanine (TTC) and Leucine (TTA). In the second group, values were below 0.6 (underrepresentation), such as those for leucine (CTA) and valine (GTT). The molecular weights ranged from 22,282.62 to 30,712.62 g mol⁻¹. In addition, the theoretical isoelectric point (pI) ranged from 4.81 to 6.6, and the instability index values were 34.3 and 38.16. A high degree of instability was observed at 1D and 5D of wheat genomes with values of 54.16 and 50.36, respectively. Principal component analysis (PCA) of the RSCU revealed that the main variation was attributed to PC1, accounting for a total variation of about 72.11%. The amino acids contributing to this variation included isoleucine, leucine, lysine, aspartic acid, and serine. PCA of the theoretical isoelectric point results found that the main variation was attributed to PC1, with a total variation of about 58.88%, and these chromosomes included 5D, 4D, 1A, 4B, and 3D of wheat genomes. These analyses provide insights into protein properties and codon usage patterns, which are valuable for understanding wheat genome function. Understanding the importance of RSCU in plant breeding helps breeders understand the mechanisms and functional aspects of wheat genomes, thereby enabling the development of wheat genomes for environmental adaptations. These results will provide a reference for nutrition and industrial applications, and will provide essential support for further breeding programs.

Screening, Characterisation, Mineral Bioleaching, and Genomics Analysis of Acidithiobacillus ferriphilus from Heavy-Metal-Rich Sulfide Acid Mine Drainage

2026-04-17T10:40:50+00:00

Microorganisms of the Acidithiobacillus genus were widely used in mineral bioleaching for industrial extraction ofvarious value metals. In this study, the isolation, characterisation, mineral bioleaching, whole genome sequencing and genomics analysis of the bioleaching strain, Acidithiobacillus ferriphilus strain QBS3, from a heavy-metal-rich sulfide acid mine drainagewas reported. This strain is a Gram-negative, micron-sized and rod-shaped bacterium with small red colonies and exhibits fast oxidation rates ofmore than 0.35 g/(L·h) for ferrous ions and more than 0.2g/(L·d) for element sulfur, and strong toxic ions resistance withminimum inhibitory concentrations (MIC) of 1000 mM for Zn(II),100 mM for As(III) and 120 mM for As(V). QBS3 also has high mineral bioleaching ability, for instance, in sphalerite bioleaching, about 20% of zinc was extracted in 14 days at 1% pulp density, and, in arsenopyrite bioleaching, about 80% leaching efficiency was obtained at a pulp concentration of 1% after 30 days. The genome of QBS3 was sequenced, annotated and analysed. The whole genome consists of one circular chromosome and one circular plasmid containing many genomic islands, prophages, CRISPRs, etc. Abundant and redundant genes related to mineral bioleaching were identified from the sequence of the genome. By the integration of characterisation, mineral bioleaching, and genomics analysis of the strain, the putative mechanism models of sphalerite bioleaching, arsenopyrite bioleaching and arsenic resistance of A. ferriphilus QBS3 were proposed. The isolated strain, the released genome sequence and the study findings in this study will greatly contribute to future applications and theoretical research of mineral bioleaching.

Combining Ability Analysis of Parental Lines and Hybrids in Snake Gourd (Trichosanthes cucumerina var. anguina L.)

2026-04-17T10:43:18+00:00

Snake gourd is one of the edible crop plants of the genus Trichosanthes, which is reported to be the largest genus of the Cucurbitaceae family. This is an important vegetable crop in India, and it has captured a prominent position among the vegetables due to its year-round cultivation, export potential and nutritive value. Developing high-yielding and well-adapted snake gourd cultivars is essential to meet the growing demands of a rising global population. This study was carried out using a line × tester mating design to assess the combining ability and genetic potential of diverse snake gourd lines for key morphological characteristics. The objective was to identify superior parental combinations and promising F₁ hybrids with high specific combining ability (SCA) for further breeding programmes. A set of seven diverse snake gourd lines was crossed with two well-adapted testers. The resulting F₁ hybrids, along with their parental lines, were evaluated for morphological traits, including growth parameters, flowering parameters, fruit parameters and biochemical parameters. The general combining ability and specific combining ability analyses were performed using INDOSTAT 2.0 statistical software. Data analysis revealed significant differences among genotypes for all evaluated traits. General combining ability (GCA) and specific combining ability (SCA) effects were estimated, and promising lines and hybrid combinations exhibiting high GCA and SCA for desirable traits were identified. The findings revealed that PKM 1, Siddapur Local and Tenali Local are among the most promising parents for overall trait performance. The crosses Tenali Local × PKM 1, Banswada Local × PKM 1, Raikur Local × PKM 1 and IC202160 × PKM 1 emerged as superior hybrids for yield, displaying significant specific combining. The results of this study provide useful information on the genetic control of morphological traits in snake gourd and confirm that the line × tester analysis is an effective tool for identifying superior parental combinations for breeding programmes aimed at developing improved snake gourd cultivars with enhanced agronomic performance.

A Rapid Agar-Based Screening Method for Acyl Homoserine Lactone (AHL) Production in Clinical Isolates of Acinetobacter baumannii

2026-04-17T10:46:17+00:00

Background: The rapid emergence and dissemination of resistant pathogens threatens to compromise the effectiveness of conventional antimicrobial therapies, thereby increasing morbidity, mortality, and healthcare burden worldwide.

Aim: This study aims to evaluate a rapid agar-based phenotypic method for detecting acyl homoserine lactone (AHL) production in clinical isolates of Acinetobacter baumannii and to examine its distribution among carbapenem-resistant and carbapenem-sensitive isolates.

Place and Duration of Study: Department of Molecular Diagnostics and Biomarkers, Gleneagles Global Hospitals, Hyderabad, India.

Methodology: Seventy-two clinical isolates of A. baumannii were subjected to antimicrobial susceptibility testing against imipenem and meropenem using the Kirby–Bauer disk diffusion method and categorised as carbapenem-resistant (CRAB, n = 58) or carbapenem-sensitive (CSAB, n = 14). AHL production was screened using a rapid agar cross-streak biosensor assay employing Chromobacterium violaceum CV026 for short-chain AHL detection and Agrobacterium tumefaciens NTL4 (pZLR4) for long-chain AHL detection. Genotypic confirmation of the quorum-sensing synthase gene abaI was performed using PCR.

Results: None of the isolates produced short-chain AHLs detectable by CV026. However, all 72 isolates induced blue-green pigmentation in A. tumefaciens, indicating production of long-chain AHLs. Based on visual intensity scoring, 80% of isolates were categorised as strong AHL producers and 20% as weak producers. The abaI gene was detected in all isolates. Long-chain AHL production was observed in both CRAB and CSAB isolates without discrimination based on carbapenem resistance status.

Conclusion: The rapid agar-based biosensor method enables simple and effective detection of quorum-sensing signal molecules in clinical isolates of A. baumannii within 24 hours. Long-chain AHL production was universally observed among both carbapenem-resistant and carbapenem-sensitive isolates, indicating that quorum-sensing activity is a common phenotypic feature of clinical strains. Although AHL production did not distinguish carbapenem resistance status, this screening approach may serve as a practical tool for studying quorum–sensing–associated virulence and persistence mechanisms in routine microbiology laboratories.

Evaluation of the Antimicrobial Properties of Avocado (Persea americana) Seed and Pulp Essential Oils

2026-04-17T10:49:09+00:00

Introduction: Avocado (Persea americana L.) is a nutritious tropical fruit belonging to the Lauraceae family, and various parts of the plant are traditionally used in the treatment of several diseases.

Aim: This study aimed to investigate the phytochemical composition and antibacterial activity of oil extracted from the seed and pulp of P. americana using the agar diffusion technique.

Methodology: Seed oil of P. americana was extracted using a Soxhlet extractor from 500 g seeds and 200 g seeds of P. americana using di-ethyl ether as solvent. Phytochemical screening was conducted following standard procedures. The extracted oils were tested for antimicrobial activity against clinical isolates of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumoniae, and Candida albicans, with conventional antibiotics as controls. Each sample was tested in triplicate, and experiments were repeated three times. Statistical analysis was performed using ANOVA, and differences were considered significant at P < 0.05.

Results: Phytochemical analysis revealed the presence of alkaloids (0.109%), saponins (1.189%), flavonoids (2.72%), polyphenols (0.202 mg/100 g), tannins (4.512 mg/100 g), and steroids (0.105 mg/100 g) in the seed oil. The result revealed P. aeruginosa to have the highest diameter of zones of inhibition of 12.00 – 30.00 mm at the concentrations of 0.1 – 0.4 g/mL, respectively. S. aureus had a diameter of zones of inhibition of 10.00 – 20.00 mm at the concentrations of 0.1 – 0.4 g/mL. E. coli had a diameter of zones of inhibition of 10.00 – 15.00 mm at the concentrations of 0.1 – 0.4 g/mL, respectively. C. albicans had a diameter of zones of inhibition of 8.00 – 13.00 mm at the concentrations of 0.1 – 0.4 g/mL, respectively; and S. pneumonia had a diameter of zones of inhibition of 8.00 – 12.00 mm at the concentrations of 0.1 – 0.4 g/mL, respectively. The results of the antimicrobial test on the seed oil showed appreciable antibacterial activities against the test organisms. The result of the test organisms was susceptible to conventional antibiotics.

Conclusion: The oil extracts of Persea americana exhibit significant antibacterial activity against several pathogenic organisms. This study addresses the research gap regarding the antibacterial potential of avocado seed and pulp oil, highlighting its promise as a natural therapeutic agent for the treatment of skin infections and encouraging further pharmacological investigations.

Evaluation of Zinc Oxide Nanoparticles for Managing Anthracnose and Southern Blight in Green Gram (Vigna radiata)

2026-04-20T13:28:28+00:00

Green gram (Vigna radiata) is frequently affected by fungal diseases such as anthracnose caused by Colletotrichum lindemuthianum, southern blight caused by Sclerotium rolfsii, powdery mildew, and cercospora leaf spot, which can hinder germination, kill plants, or significantly reduce yield. This study investigates the antifungal activity of green-synthesised zinc nanoparticles (ZnNPs) against C. lindemuthianum and S. rolfsii using the poisoned food technique. ZnNPs were synthesised using plant extracts of mehandi (Lawsonia inermis), neem (Azadirachta indica), marigold (Tagetes erecta), and ginger (Zingiber officinale), following compatibility assessment with the test pathogens. Different concentrations (100, 250, and 500 ppm) of ZnNPs were evaluated alongside corresponding plant extracts and zinc nitrate hexahydrate (250 ppm).

Results indicated significant fungistatic activity, with Mehandi ZnNps at 500ppm exhibiting the highest efficacy, demonstrating minimal mycelial growth (28.00mm) and a growth inhibition rate of 68.88%, followed by Marigold and Neem ZnNps against Colletotrichum. As for Sclerotium, Neem ZnNps at 500 ppm exhibited the highest efficacy, demonstrating minimal mycelial growth (15.00 mm) and a growth inhibition rate of 83.33%, followed by ginger and Mehandi. All tested ZnNps concentrations outperformed their respective plant extracts and Zinc nitrate hexahydrate, confirming the potential of green-synthesised ZnNp as effective agents. These findings highlight the potential of green-synthesised ZnNps as eco-friendly and effective antifungal agents, offering a sustainable alternative to chemical fungicides for managing fungal diseases in green gram. Further studies are recommended to investigate the mechanisms of antifungal action, field-level efficacy, and environmental impact, including effects on soil health and non-target organisms.