Microbial interactions within diverse ecosystems are intricately governed by the dynamic interplay of exopolysaccharides (EPSs) produced by microorganisms. This review delves into the multifaceted roles of EPS in microbial signalling, quorum sensing (QS), and community dynamics, highlighting their significance in orchestrating cooperative behaviours and shaping community structures. EPSs serve as pivotal signalling molecules, influencing chemical communication and promoting intricate interactions among microorganisms. The integration of EPS into QS mechanisms adds an additional layer of complexity, allowing microorganisms to assess population density and synchronise communal responses. Furthermore, EPSs actively contribute to community dynamics by influencing spatial organisation, adhesion, and resistance to environmental stressors. By providing comprehensive knowledge of EPS dynamics, this review offers valuable insights into microbial ecology, serving as a foundational resource for future research. It will benefit the research community by advancing our understanding of microbial ecosystems, with broad applications in biotechnology, environmental science, and beyond.

The current study focuses on optimizing, characterizing, and purifying a thermostable amylase from thermophilic bacteria Geobacillus icigianus (BITSNS038). The amylase was produced optimally at 18–24 h of incubation in the presence of starch and tryptone at 7.5 and 3.0 g/L, respectively (pH 7.0, 70°C, and 150 rpm). K_m, V_max values for starch were 2.17 mg/mL and 4.16 U/mL respectively. The enzyme showed excellent thermal stability at 70°C, retaining 62.5% residual activity after 8 h and a reduced deactivation rate constant (k_d) of 0.001. When tested for its efficacy in starch hydrolysis, it showed 34.5% hydrolysis of corn starch slurry and antibiofilm activity, but no antimicrobial activity was noticed. The ultrafiltration led to partial purification of amylase showed 2.67-fold purification with a molecular weight in the range of 45 and 66 kDa. This is probably the first-ever report on a thermostable amylase from G. icigianus and its extensive potential uses.

The essential oil yield and quality of Tagetes minuta was field tested in north Indian plain conditions of Lucknow, India in winter (rabi) season of November 1997 to April 1998. The shoot oil distilled from the crop of Banuri land race at full flowering stage was rich in dihydrotagetone (32.0%), (Z)-tagetone (16.7%) and (Z)-β-ocimene (133%). In comparison to the oils distilled from flower bearing plants, the oil from plants at vegetative stage(s) of growth contained (E)- and (Z)-tagetenones and (E)- and (Z)-tagetones at higher levels (27.1% and 31.2%, respectively) and dihydrotagetone and (Z)-β-ocimene at lower levels (13.6% and 6.1%, respectively). The oils obtained from the leaves of plants bearing flowers (capitula) at different stages of development were pre-eminent in dihydrotagetone, present in 50-60% concentration. The capitula oils were somewhat similar to leaf oils of reproductively mature plants in their monoterpenoid composition.

Thermophiles are the microorganisms which thrive under extreme conditions such as high temperature, making them significant for scientific interest. This study provides information based on isolation of thermophilic strain from Surajkund and Ramkund, hot spring of Jharkhand at 50, 60 and 70 °C. Two of the best isolates were used for the extraction of exopolysaccharides. Additionally, the lyophilized product obtained was further analyzed for protein and total sugar estimation. The FTIR analysis revealed the presence of different functional groups such as hydroxyl, C–H stretching, vibration of aliphatic CH₂ and glycosidic linkage, thus proving the product obtained from bacteria was an exopolysaccharides The FESEM analysis of exopolysaccharides show varying surface morphology that is from porous to globular structure. Based on 16S rRNA sequences, the isolates from Surajkund (ON795919) and Ramkund (ON795916) were different strains of Bacillus licheniformis. This is the first report on exopolysaccharide secreting thermophilic strain from these hot springs. Graphical Abstract