The poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from cyanobacteria is an environmentally friendly biodegradable polymer. The low yield of PHBV’s production is the main hindrance to its sustainable production, and the manipulation of PHBV production processes could potentially overcome this obstacle. The present research investigated evolutionarily divergent cyanobacteria obtained from local environments of Thailand. Among the strains tested, Cyanosarcina sp. AARL T020, a hot spring cyanobacterium, showed a high rate of PHBV accumulation with a fascinating 3-hydroxyvalerate mole fraction. A two-stage cultivation strategy with sole organic carbon supplementation was successful in maximizing cyanobacterial PHBV production. The use of an optimized medium in the first stage of cultivation provided a 4.9-fold increase in biomass production. Subsequently, the addition of levulinic acid in the second stage of cultivation can induce significant biomass and PHBV production. With this strategy, the final biomass production and PHBV productivity were increased by 6.5 and 73.2 fold, respectively. The GC-MS, FTIR, and NMR analyses confirmed that the obtained PHBV consisted of two subunits of 3-hydroxyvaryrate and 3-hydroxybutyrate. Interestingly, the cyanobacterial PHBV contained a very high 3-hydroxyvalerate mole fraction (94%) exhibiting a low degree of crystallinity and expanding in processability window, which could be applied to polymers for desirable advanced applications.

Objective: The objective of the present work is to analyze that the extracts of 25 Thai aromatic plants used in Thai food recipes were subjected to evaluated antimicrobial activity against Fusobacterium nucleatum and Streptococcus mutans which have been known as bacterial inducing halitosis.Methods: Disk diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) by broth microdilution were used to determine the antibacterial activity.Results: The results revealed that three plant extracts, namely Piper betle Linn., Eupatorium stoechadosmum Hance, and Alpinia galangal (L.) Wild can inhibit the growth of both halitosis inducing bacteria with strong activity. Among these, the extract of P. betle Linn. is the most effective in inhibiting both bacteria followed by E. stoechadosmum Hance and A. galangal (L.) Wild, respectively. The MIC (mg/ml) values of the extracts which can inhibit F. nucleatum were ranging from 1.56 to 12.50, and the MBCs (mg/ml) values were ranging from 3.125 to 25.00. In addition, the MICs and MBCs of the extracts which can inhibit S. mutans were found that 1.56–25.00 and 3.125–50.00, respectively.Conclusion: The extracts obtained from P. betle, A. galangal, and E. stoechadosmum displayed good activity against F. nucleatum and S. mutans and these extracts could be a potential source of new antimicrobial agents.

Objective: The objective of the present work is to analyze that the extracts of 25 Thai aromatic plants used in Thai food recipes were subjected to evaluated antimicrobial activity against Fusobacterium nucleatum and Streptococcus mutans which have been known as bacterial inducing halitosis.Methods: Disk diffusion method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) by broth microdilution were used to determine the antibacterial activity.Results: The results revealed that three plant extracts, namely Piper betle Linn., Eupatorium stoechadosmum Hance, and Alpinia galangal (L.) Wild can inhibit the growth of both halitosis inducing bacteria with strong activity. Among these, the extract of P. betle Linn. is the most effective in inhibiting both bacteria followed by E. stoechadosmum Hance and A. galangal (L.) Wild, respectively. The MIC (mg/ml) values of the extracts which can inhibit F. nucleatum were ranging from 1.56 to 12.50, and the MBCs (mg/ml) values were ranging from 3.125 to 25.00. In addition, the MICs and MBCs of the extracts which can inhibit S. mutans were found that 1.56–25.00 and 3.125–50.00, respectively.Conclusion: The extracts obtained from P. betle, A. galangal, and E. stoechadosmum displayed good activity against F. nucleatum and S. mutans and these extracts could be a potential source of new antimicrobial agents.