Diseño innovador para la obtención y caracterización de un bioplástico utilizando como materia base la fibra de la cáscara de coco y papaya / Innovative design for obtaining and characterizing a bioplastic using as a base material the fiber of the coconut shell and papaya fiber

Los plásticos se producen a partir del petróleo. Estos polímeros perduran en la naturaleza por largos períodos de tiempo y, por tanto, se acumulan, generando así grandes cantidades de residuos sólidos. El objetivo principal de esta investigación es producir, a escala de laboratorio, un bioplástico a partir de la fibra contenida en la cáscara de coco, que pueda servir de materia prima para la elaboración de productos biodegradables.

Plastics are produced from oil. These polymers persist in nature for long periods of time and, therefore, they are accumulated in large amounts of solid waste. The main objective of this research is to produce, on a laboratory scale, a bioplastic from the fiber contained in the coconut shell, which can serve as raw material for the production of biodegradable products.

Poly-hydroxybutyrate (PHB) production by Halomonas elongata BK AG 18 indigenous from salty mud crater at central Java Indonesia

Aims: Bioplastic is a biodegradable polymer produced by particular microorganism as a secondary metabolite. Some halophilic bacteria belonging to Halomonas genus have been reported to be a potential of polyhydroxybutyrate (PHB) producer. This study aims to explore the potential of an indigenous halophilic bacterial isolate, H. elongata BK-AG18, as bioplastic producer. The indication as bioplastics producer was evaluated by growing in nile red-containing medium and bacterial colonies displayed bright orange fluorescent under ultraviolet light. Methodology and results: Bioplastic production by H. elongata BK-AG 18 was achieved using modified glucosecontained High Medium (HM) after incubated in a rotary shaker for 22 h, 37 °C, 150 rpm. The bioplastic was extracted with chloroform and sodium hypochlorite (1:1) and precipitated in methanol. The highest yield of bioplastic production was 21.36% of the dried bacterial cell weight. The structural characterizations of the bioplastics using Fourier transformed infrared (FTIR), 1H and 13C nuclear magnetic resonances (NMR) spectroscopies showed high similarity to the spectral pattern of poly-hydroxybutyrate (PHB). Further characterization using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed that the decomposition and melting temperature at 266 °C and 166.5 °C of the PHB, respectively. The result of PHB has a low degree of crystallinity (9.5%) that close to the rubber-like polymer. Conclusion, significance and impact of study: This study revealed the high potential of H. elongata BK-AG 18 as PHB producer with high mechanical properties.

A purple non-sulfur bacterium producing polyhydroxybutyrate and the conserved region of pha synthase gene / Bactéria púrpura não sulfurosa produtora de polihidroxibutirato e a região conservada do gene pha sintase

This study aimed to screen purple non-sulfur bacteria capable of accumulating granules or polyhydroxybutyrate (PHB) inside the cells, identify the potent strain, assay the enzyme or PHA synthase, and compare the PHB synthase gene with that of related strains. A total of 58 strains of purple non-sulfur bacteria were isolated from 108 samples of chicken feces in the chicken-egg farm of the Department of Animal Science, Faculty of Natural Resources at Prince of Songkla University, Hat Yai, Thailand. After cultivating the bacteria in glutamate malate (GM) medium without added glutamic acid under light (3,000 Lux) at 35oC for 5 days, the intracellular biopolymer granules of the bacteria were observed by using a Confocal Laser Scanning Microscope (CLSM) with excitation and emission wavelength of 530 and 605 nm, respectively. Gas chromatography (GC) was carried out for quantitative analysis of PHB. There were five strains, CH12, CH52, CH72, CH90 and CH92, showed biopolymer granules under CLSM, and accumulated PHB 5, 1.7, 1.5, 1.4 and 1.8% (w w-1) of the cell dry weight (CDW), respectively. The 16S rDNA sequence analysis of CH12 strain showed a high homology of 100% correlation to that of Rhodopseudomonas palustris strain NCIB8288. Regarding the taxonomic characteristics and 16S rDNA sequence analysis, CH12 strain was identified as Rps. palustris NCIB8288. The PHA synthase activity of the crude extract from CH12 strain was 25 units/mL. The conserved regions could be aligned and selected among 5 strains of Rhodopseudomonas palustris (strains BisA53, TIE-1, CGA009, HaA2 and BisB18). The purified PCR product was obtained for further studies.

Este estudo teve como objetivo rastrear bactérias púrpuras não sulfurosas capazes de acumular grânulos ou polihidroxibutirato (PHB) dentro das células, identificar a estirpe potente, ensaiar a enzima ou PHA sintaxe, e comparar com o gene PHB sintase com aquele de estirpes relacionadas. Um total de 58 estirpes de bactérias púrpuras não sulfurosas foram isoladas a partir de 108 amostras de fezes de galinhas na granja produtora de ovos do Departamento de Ciência Animal, Faculdade de Recursos Naturais da Universidade Prince of Songkla, Hat Yai, Tailândia. Depois de cultivar as bactérias em um substrato de glutamato/malato (GM), sem ácido glutâmico adicionado, sob luz (3000 lux) a 35 ºC durante 5 dias, os grânulos de biopolímeros intracelulares das bactérias foram observados utilizando um microscópio confocal (do inglês Confocal Laser Scanning Microscope - CLSM) com comprimentos de onda de excitação e emissão de 530 e 605 nm, respectivamente. A cromatografia gasosa (do inglês Gas chromatography - GC) foi realizada para uma análise quantitativa de PHB. Havia 5 estirpes, CH12, CH52, CH72, CH90 e CH92, que mostraram grânulos biopoliméricos quando submetidos ao CLSM, e PHB-5 acumulado de 1.7, 1.5, 1.4 and 1.8% (w w-1) do peso celular seco (do inglês cell dry weight - CDW), respectivamente. A análise da sequência do rDNA 16S da estirpe CH12 demonstrou uma alta correlação de homologia de 100% para aquela da estirpe NCIB8288 da Rhodopseudomonas palustris. Em relação às características taxonômicas e da análise da sequência do rDNA 16S, a estirpe CH12 foi identificada como Rps. palustris NCIB8288. A atividade da PHA sintase do extrato bruto da estirpe CH12 foi de 25 unidades/mL. As regiões conservadas puderam ser alinhadas e selecionadas entre 5 estirpes de Rhodopseudomonas palustris (BisA53, TIE-1, CGA009, HaA2 e BisB18). O produto purificado da reação em cadeia da polimerase - PCR foi obtido para estudos futuros.

Production of Polyhydroxybutyrate by Bacillus axaraqunsis BIPC01 using Petrochemical Wastewater as Carbon Source

The aim of this study was to use petrochemical wastewater as the source of carbon for the production of polyhydroxyalkanoates (PHA) in an effort to decrease its cost of production. For this purpose, PHA producing bacteria were isolated from the petrochemical wastewater of Bandar Imam, Iran. The purified colonies were screened for PHA by Sudan Black B and Nile Blue A staining. Among positively stained bacteria, the best PHA producer was selected on the basis of cell growth, PHA content and the monomer composition of PHA. The phenotypic and genotypic identification this isolate showed it to be Bacillus axaraqunsis. The PHA was produced at a cell density of about 9.46 g/l of maximum concentration of 6.33g/l l, corresponding to 66% of cell dry weight. These results showed that B. axaraqunsis BIPC01 could be a potent PHA producer using wastewater for industrial purpose and simultaneously reducing the environmental pollution.