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This study investigates the effects of different strategies on poly(3-hydroxybutyrate)-P(3HB) production in a fed-batch bioreactor by Bacillus megaterium using candy industry effluent (CIE), sucrose, and rice parboiled water (RPW) as carbon sources. In biosynthesis, kinetic and stoichiometric parameters of substrate conversion into products and/or cells, productivity, instantaneous, and specific conversion rates were evaluated. The maximum concentration of P(3HB) was 4.00 g.L -1 (77% of the total dry mass) in 42 h of cultivation in minimal medium/RPW added with a carbon source based on CIE, demonstrating that the fed-batch provided an increase of approximately 22% in the polymer concentration and 32% in the overall productivity in relation to medium based on commercial sucrose. Fed-batch cultivation also had the advantage of avoiding the extra time required for inoculum preparation and sterilization of the bioreactor during the batch, which thereby increased the overall industrial importance of the process. Effluents from the candy, confectionery, and/or rice parboiling industries can be used as alternative substrates for P(3HB) production at a low cost., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The increasing use of synthetic polymers and their disposal has raised concern due to their adverse effects on the environment. Thus, other sustainable alternatives to synthetic plastics have been sought, such as polyhydroxyalkanoates (PHAs), which are promising microbial polyesters, mainly due to their compostable nature, biocompatibility, thermostability, and resilience, making this biopolymer acceptable in several applications in the global market. The large-scale production of PHAs by microorganisms is still limited by the high cost of production compared to conventional plastics. This review reports some strategies mentioned in the literature aimed at production and recovery, paving the way for the bio-based economy. For this, some aspects of PHAs are addressed, such as synthesis, production systems, process control using by-products from industries, and advances and challenges in the downstream. The bioplastics properties made them a prime candidate for food, pharmaceutical, and chemical industrial applications. With this paper, it is possible to see that biodegradable polymers are promising materials, mainly for reducing the pollution produced by polymers derived from petroleum., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© King Abdulaziz City for Science and Technology 2023, Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.)

This in vitro study aimed to evaluate the growth-inhibitory effects against periodontal disease-causing bacteria and cytotoxic effects against mouse fibroblast cells of the Stryphnodendron adstringens (barbatimão) hydroalcoholic extract. The contents of phenols and tannins in the extract were determined. The growth-inhibitory activity of the barbatimão was evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The viability of fibroblast cells was analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay at 24 and 48 h post-treatment. The MIC values of the extract against Prevotella intermedia, Porphyromonas gingivalis, and Fusobacterium nucleatum were 0.05, 0.125, and 2 mg mL-1, respectively, while the MBC values were 4, 2, and 2 mg mL-1, respectively. The viability rate of barbatimão (0.25 mg mL-1)-treated L929 cells was higher than that of chlorhexidine (0.12%)-treated L929 cells at 48 h post-treatment. The contents of total phenolics and total tannins in the extract were 837.39 ± 0.10 and 785.82 ± 0.14 mg of tannic acid equivalent per gram of the extract, respectively. These findings indicate that the barbatimão hydroalcoholic extract, which exerted potent growth-inhibitory effects against the test microbial species and low cytotoxic effects on fibroblasts, has potential applications in the development of novel mouthwash products., (© The Author(s) 2023. Published by Oxford University Press on behalf of Applied Microbiology International.)