ABSTRACT
Sugarcane is one of the most important industrial crops in Vietnam and covers a total of 127,000 hectares of plantation area. In the season 2020-2021, Vietnam has produced 0.763 million tons of sugar (accounting for 0.34% total world sugar production). A current sugarcane production of 7.498 million tons is being used mainly for sugar production for direct consumption, ethanol production, bio-electricity and fertilization. To ensure crop sustainability, various policies and plans have been implemented. Crop breeding and zoning improvement programme significantly influence sugarcane production and sugar yield. Over 25 years since the programme "one million ton of sugar" was promoted, Vietnam currently possesses 25 sugar mills with a total capacity of 110,000 tons of sugarcane per day. Major problems of sugarcane industry as well as research and development have been discussed in this review. Recent research and development work focused on the added values of co-products to ensure sustainability of the sugarcane industry. Molasses will be used for ethanol production, and bagasse is used as the biomass for the alternative energy. Sugarcane and sugar would be the main feedstocks for those bio-economy growths in Vietnam. To keep the sustainable development of the sugar industry, and to meet the demand of the food and non-food requirements, it is necessary to upgrade the sugar value chain through the adoption and the development of co-products of the sugar industry.
ABSTRACT
To date, endophytic actinomycetes have been well-documented as great producers of novel antibiotics and important pharmaceutical leads. The present study aimed to evaluate potent bioactivities of metabolites synthesized by the strain LCP18 residing in the Vietnamese medicinal plant Litsea cubeba (Lour.) Pers towards human pathogenic bacteria and human cancer cell lines. Endophytic actinomycete strain LCP18 showed considerable inhibition against seven bacterial pathogens and three human tumor cell lines and was identified as species Streptomyces variabilis. Strain S. variabilis LCP18 was phenotypically resistant to fosfomycin, trimethoprim-sulfamethoxazole, dalacin, cefoxitin, rifampicin, and fusidic acid and harbored the two antibiotic biosynthetic genes such as PKS-II and NRPS. Further purification and structural elucidation of metabolites from the LCP18 extract revealed five plant-derived bioactive compounds including isopcrunetin, genistein, daidzein, syringic acid, and daucosterol. Among those, isoprunetin, genistein, and daidzein exhibited antibacterial activity against Salmonella typhimurium ATCC 14,028 and methicillin-resistant Staphylococcus epidermidis ATCC 35,984 with the MIC values ranging from 16 to 128 µg/ml. These plant-derived compounds also exhibited cytotoxic effects against human lung cancer cell line A549 with IC50 values of less than 46 µM. These findings indicated that endophytic S. variabilis LCP18 can be an alternative producer of plant-derived compounds which significantly show potential applications in combating bacterial infections and inhibition against lung cancer cell lines.
