No abstract

Aims: To isolate and characterize oil‐degrading microorganisms from contaminated (scale) soil. 
Methods and Results: Oil‐degrading microorganisms were isolated from enrichment cultures of scale soil. Each isolate was identified using 16S rDNA gene and oil degradability was determined on both unused and used lubricating oil. The weight of the extracted remaining oil revealed that most isolates degraded unused lubricating oil more than used lubricating oil. Chemical composition of oil analysed by TLC‐FID and GC‐MS demonstrated that Nocardia simplex W9 degraded used oil the best, and resulted in a decrease in saturates, aromatics and resins to 52·46, 38·13 and 18·81%, respectively. 
Conclusions:Nocardia simplex W9 is the best degrader, among all the isolates, on both used and unused lubricating oil. 
Significance and Impact of the Study: The presence of Nocardia simplex W9 in scale soil enables iron to be recycled by biodegradation.

Aims:  To select a carotenoid‐hyperproducing mutant and to formulate pineapple juice as a carotenoid production medium. Methods and Results:  Yeast strain of Xanthophyllomyces dendrorhous mutant GM 807 (derived from gamma irradiation) and the mutant n78 (from neutron irradiation) were selected based on higher carotenoid production in diluted pineapple juice as a medium. The selected strain was evaluated under various concentrations of pineapple juice. The results obtained in the study demonstrate that the mutant GM 807 enhanced production by 65·8% when using pineapple juice as medium at 10% dilution in place of yeast malt medium. Conclusion:  Pineapple juice could be used as a sole medium for carotenoid production. Significance and Impact of the Study:  Our results provide useful information for the design of production media for carotenoids to be used in various applications.

Astaxanthin is a natural carotenoid pigment with powerful antioxidant capacity which has been reported for beneficial effects on human health to prevent cancers and anti-degenerative diseases. Bioavailability of astaxanthin is however limited due to insoluble and instable properties of its lipophilic nature. This study describes the cytotoxicity and astaxanthin delivery using a surfactant (tween 80) and penetration enhancers (methyl -cyclodextrin and liposome) to enhance astaxanthin bioavailability in human hepatocellular carcinoma cell line. Toxicity of tween 80 and methyl -cyclodextrin increased with concentration. Liposome did not alter cell viability relative to untreated controls, regardless of concentration tested. Cellular uptake among delivery vehicles was compared at 24 hours and was found to be higher than that of astaxanthin without a vehicle. The cellular uptake rate was highest when liposome was used as the delivery vehicle. This finding aids in the development of design criteria for vehicles for delivery of antioxidants to cells.

This study investigated the cytotoxicity of asiatic acid (AA) encapsulated in different protein-carbohydrate matrices in human colon adenocarcinoma SW620, human hepatoblastoma HepG2 and diploid monkey kidney cells (Vero). Mungbean protein concentrate (MPC) and mungbean protein hydrolysate (MPH) in lactose (L) or lactose-maltodextrin (LM) mixture, were used to fabricate matrices encapsulating AA during lyophilisation. The cytotoxicity of AA was in a dose-dependent manner for HepG2 and SW620 cells, but not for Vero cells. The 50% inhibitory concentrations (IC 50 ) of AA in HepG2 and SW620 were 120 and 130 lm respectively. The IC 50 of AA encapsulated in MPH-L matrix in HepG2 was reduced from that of AA alone to 80 lm (P < 0.05). Study of the anti-cancer activity of AA, in the absence and presence of food matrices, revealed that an MPH-L matrix led AA to cause more apoptosis deaths in HepG2 cells than either a MPC-L matrix or pure AA.Influences of food matrices on cytotoxicity of asiatic acid K. Jirasripongpun et al.Influences of food matrices on cytotoxicity of asiatic acid K. Jirasripongpun et al.