Search

IntroductionThe marine microalga Isochrysis galbana is prolific producer of fucoxanthin, which is a xanthophyll carotenoid with substantial global market value boasting extensive applications in the food, nutraceutical, pharmaceutical, and cosmetic industries. This study presented a novel integrated experimental approach coupled with machine learning (ML) models to predict the fucoxanthin content in I. galbana by altering the type and concentration of phytohormone supplementation, thus overcoming the multiple methodological limitations of conventional fucoxanthin quantification.MethodsA novel integrated experimental approach was developed, analyzing the effect of varying phytohormone types and concentrations on fucoxanthin production in I. galbana. Morphological analysis was conducted to assess changes in microalgal structure, while growth rate and fucoxanthin yield correlations were explored using statistical analysis and machine learning models. Several ML models were employed to predict fucoxanthin content, with and without hormone descriptors as variables.ResultsThe findings revealed that the Random Forest (RF) model was highly significant with a high R2 of 0.809 and RMSE of 0.776 when hormone descriptors were excluded, and the inclusion of hormone descriptors further improved prediction accuracy to R2 of 0.839, making it a useful tool for predicting the fucoxanthin yield. The model that fitted the experimental data indicated methyl jasmonate (0.2 mg/L) as an effective phytohormone. The combined experimental and ML approach demonstrated rapid, reliable, and cost-efficient prediction of fucoxanthin yield.DiscussionThis study highlights the potential of machine learning models, particularly Random Forest, to optimize parameters influencing microalgal growth and fucoxanthin production. This approach offers a more efficient alternative to conventional methods, providing valuable insights into improving fucoxanthin production in microalgal cultivation. The findings suggest that leveraging diverse ML models can enhance the predictability and efficiency of fucoxanthin production, making it a promising tool for industrial applications.

Aqueous alcohol extracts of the leaves of Euphorbia nivulia were investigated for antimicrobial activity. Nineteen different bacterial strains and two fungal cultures were used. The results indicate that the aqueous alcohol extracts were active at concentrations ranging from 3-12.5 µg/ml for Gram-negative and 12.5-200 µg/ml for Gram-positive bacteria. The activity was compared with known antibiotics such as streptomycin and nystatin. [ABSTRACT FROM AUTHOR]

A study is conducted to test the biological conversion of sulfides using immobilized cells of Thiobacillus sp. in fluidized bed bioreactor. The Thiobacillus sp are isolated from aerobic sludge of distillery and dairy effluent treatment plant using standard methods of isolation and enrichment. Experiments were conducted in a batch fluidized bed bioreactor using calcium alginate immobilized cells of isolated Thiobacillus sp. The batch fluidized bed bioreactor is operated for 168 hours with an initial sulfide concentration of 150 mg/l, at the end of 168 hours 100% sulfide oxidation is achieved by the continuous supply of sterile air as oxidant. During the operational period, biomass concentration, pH, sulfate formation is recorded.

The pharmaceutical industrial effluents, which include several organic solvents and other toxic chemicals, are generally treated by aerobic process, which is cost intensive in nature. The alternative anaerobic route to degrade the toxic effluents is attractive due to the lower cost of treatment and the generation of gas, which can supplement the energy requirements. There are few reports on the anaerobic treatment of the pharmaceutical effluents. In the present investigation, the effluents from a bulk drug industry, which utilizes several organic chemicals, have been taken to assess their applicability for anaerobic treatment. The organic loading rates were varied from 0.25 kg/m3/day to 2.5 kg/m3/day and the COD reduction was found to be in the range of 60 to 80%. Long term operation of an anaerobic suspended film contact reactor carried out with 1.25 kg/m3/day was found to be optimum. The biogas generated during the degradation process was monitored and the methane content was found to be 60-70%.

A series of dihydrofurobenzoxazolin-2(3H)-ones and their derivatives were synthesized. The structures of the compounds have been elucidated by IR, mass, 1H-NMR spectra and elementary analysis. The in vitro activity of these compounds was investigated against Gram-positive and Gram-negative bacteria and also against Candida albicans. 7,7-Dimethyl-7,8-dihydro-furo[2,3-g]benzoxazolin-2(3H)-one (compound 2) proved to be more potent than compound 1. Compound 3 also showed significant activity against all the microbes tested. Compounds 4 and 5 were more effective against Gram-positive bacteria than Gram-negative bacteria but inactive against C. albicans.

The preparation and in vitro antibacterial activity of a novel series of gem-diphenyl-spiro-cyclopropano-oxazolones (cis-1,2,2,5-tetraphenyl 6-oxa-4-azaspiro[2.4]hept-4-en-7-one) are described. The overall activity of these compounds was higher than that of the 2-aryl(alkyl)4-ylidene-oxazol-5-ones (azlactones). The gem-diphenyl-spiro-cyclopropano-oxazolones 1-4 have emerged as the most potent derivatives when tested against bacteria.