Biosurfactants are surface‐active compounds synthesized by microorganisms that serve as eco‐friendly alternatives to synthetic surfactants in industrial and environmental applications. This study compared four common screening assays—hemolysis, oil displacement (ODA), drop collapse, and emulsification index (E24)—to evaluate biosurfactant‐producing bacteria from diverse habitats. A total of 154 morphologically distinct isolates were obtained from oil‐contaminated soil, kitchen chimney soot, Himalayan alpine soil, and Southern Ocean sediments. Contaminated samples showed higher microbial loads (up to 2.64 × 10
8
CFU/g) and a greater frequency of positive strains. Hemolysis yielded the highest positives (56.4%), followed by ODA (26%), drop collapse (22.7%), and E24 (19.5%). Fifteen isolates (9.7%) were positive across all tests, with four strains (HUS20, BS108, SOE17, and KC15) exhibiting strong emulsification activity (53%–60%). 16S rRNA gene analysis identified these key producers as members of the genera
Pseudomonas
,
Cytobacillus
, and
Streptomyces
, underscoring the taxonomic diversity of efficient biosurfactant‐producing bacteria. Statistical analysis indicated a positive but statistically non‐significant correlation between microbial abundance and biosurfactant activity (
r
= 0.69,
p
= 0.31). The findings highlight ODA as a more reliable and functionally relevant primary screening tool for identifying potent biosurfactant producers from both polluted and pristine environments.
Kishore Kumar Annamalai, R. Manikkam, Manigundan Kaari et al.· Journal of Surfactants and D...· 0 citations
The common bean (
Phaseolus vulgaris
L.) is a vital legume crop for advancing global food security, climate‐resilient agriculture, and soil fertility. However, the yields of Western Himalayan common bean remain low due to nutrient‐deficient soils, traditional farming practices, and a lack of improved inputs. This study evaluated the effect of
Pseudomonas jesenii
MP1 and
Pseudomonas palleroniana
N26 for enhancing common bean yield and nutrition under farmer‐managed conditions in Uttarakhand. Both bioinoculants significantly increased crop yield across the years and locations, with improvements ranging from 4.84% to 25.05% compared to the control (untreated). An increase of 22.70% in crop yield was recorded with the N26 treatment, while the highest improvement (25.05%) was recorded in the MP1 treatment. Microbial treatments significantly improved the seed physical traits, including weight, length, width, and thickness. Nutritional analysis indicated that MP1 increased total carbohydrate and protein content, whereas N26 enhanced antioxidant activity (2,2‐diphenyl‐1‐picrylhydrazyl‐DPPH assay) and methionine content. A linear mixed model showed significant effects of treatment on yield, protein content, seed thickness, and antioxidant activity. Principal component analysis displayed strong loading of DPPH activity and yield in PC1, while protein and methionine dominated PC2; site clustering reflected microclimatic variability. Pearson's correlation analysis exhibited positive associations among seed physical traits and yield, whereas antioxidant activity and methionine were negatively correlated with protein (
p
< 0.01). The results confirm these strains are effective, sustainable biofertilizers that improve Himalayan common bean yield and nutrition, promoting resource‐efficient agriculture aligned with sustainable development goals 2 and 12.
Y. Bisht, A. Jugran, Ajay Veer Singh et al.· Agronomy Journal· 0 citations