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Bacterial cellulose (BC) is emerging as an attractive large-scale polymer due to its superior properties. The dominant static culture for BC fermentation by bacteria or microbial consortium results in low productivity. Agitated culture, as an industrially projected technique, has been widely investigated but exclusively for cellulose-producing bacterial strains. Addressing this concern and evaluating the potential of residues as feedstock, this study highlights the utilization of microbial consortium BA2 and seven agro-industrial wastes including cocoa husks, sugarcane bagasse and others. Remarkably, rice bran (RB) appears as a promising substrate, achieving 2.14 g/L (dry basis) and outperforming the traditional HS medium, evident from a 15-day fermentation. A complex interplay between oxygen availability, glucose consumption and BC yield was revealed; while orbital and magnetic stirring with forced air ventilation (AFV) showed low BC yields and early biomass saturation, 4.07 g/L (dry basis) was targeted by magnetic stirring at 100 rpm from the start using only headspace air. However, beyond controlled operating conditions, mechanical agitation and favorable cellulose adhesion to metal in the stirred tank bioreactor negatively affect BC yield. This pattern uncovers the need for a further approach to the design of bioreactors when the microbial consortium is considered. [ABSTRACT FROM AUTHOR]

The effects of ionizing radiation in promoting the abiotic degradation mechanisms in oxo‐degradable plastic bags were studied. Commercial plastic bags, containing pro‐oxidant additives, were irradiated with gamma photons and accelerated electrons at doses of 5 and 10 kGy. Then, the irradiated bags were exposed to abiotic degradation, either thermal aging or accelerated weathering. Mechanical and microstructural characterizations were performed to follow the degradation. Plastic bags containing additives did not show important changes in their structure after ionizing radiation and thermal aging. Meanwhile, accelerated weathering combined with gamma photons irradiation produce fragmentation of all the samples after 120 h of degradation. It was concluded that the combination of ionizing radiation and accelerated weathering allows the breakage of polyethylene chains trough accelerating the activation of pro‐oxidant additive. Additionally, polyethylene molecules are degraded with pre‐treatment of ionizing radiation even if they do not contain the pro‐oxidant additive. [ABSTRACT FROM AUTHOR]

In order to characterize the bromatological composition of three agricultural wastes: maize (Zea mays), sorghum (Sorghum sp.) and chickpea (Cicer arietinum) in Sinaloa state, Mexico, selected for their possibilities of use in ruminants feeding, was determined to the samples (n = 21) of these by-products the percentage of crude protein, neutral detergent fiber, acid detergent fiber, hemicellulose and cellular content. The crude protein, neutral detergent fiber, acid detergent fiber and cellular content showed differences (P ˂ 0.0001) between treatments, while hemicellulose was similar in the three agricultural wastes. The obtained results show that the chickpea waste has a better chemical composition than the rest. They also suggest performing physiological tests on ruminants to determine the inclusion levels and potential use of wastes, in order to determine their nutritional value. [ABSTRACT FROM AUTHOR]