Sustainable synthesis pathways: Bacterial nanocellulose from lignocellulosic biomass for circular economy initiatives.

The hydrothermal pretreatment process stands out as a pivotal step in breaking down the hemicellulosic fraction of lignocellulosic biomasses, such as sugarcane bagasse and eucalyptus sawdust. This pretreatment step is crucial for preparing these materials for subsequent processes, particularly in food applications. This technique aims to disintegrate plant wall components like cellulose, hemicellulose, and lignin, and facilitating access in later phases such as enzymatic hydrolysis, and ultimately making fermentable sugars available. In this study, sugarcane bagasse and eucalyptus sawdust biomass underwent hydrothermal pretreatment at specific conditions, yielding two key components: dry biomass and hemicellulose liquor. The primary focus was to assess the impact of hydrothermal pretreatment followed by enzymatic hydrolysis, using the Celic Ctec III enzyme cocktail, to obtain fermentable sugars. These sugars were then transformed into membranes via strain Gluconacetobacter xylinus bacterial biosynthesis. Notably, the addition of a nitrogen source significantly boosted production to 14.76 g/ in hydrolyzed sugarcane bagasse, underscoring its vital role in bacterial metabolism. Conversely, in hydrolyzed eucalyptus, nitrogen source inclusion unexpectedly decreased yield, highlighting the intricate interactions in fermentation media and the pivotal influence of nitrogen supplementation. Characterization of membranes obtained in synthetic and hydrolyzed media through techniques such as FEG-SEM, FTIR, and TGA, followed by mass balance assessment, gauged their viability on an industrial scale. This comprehensive study aimed not only to understand the effects of pretreatment and enzymatic hydrolysis but to also evaluate the applicability and sustainability of the process on a large scale, providing crucial insights into its feasibility and efficiency in practical food-related scenarios, utilizing nanocellulose bacterial (BNC) as a key component.

Purification and characterization of a novel extracellular serine-protease with collagenolytic activity from Aspergillus tamarii URM4634.

An extracellular serine-protease from Aspergillus tamarii URM4634 was purified and characterized. The possibility of using Aspergillus tamarii URM4634 protease in detergent formulations and collagenolytic activity was investigated. The protease demonstrated excellent stability at pH range 7.0-11.0, the optimum being at pH 9.0. The enzyme was stable at 40 °C for 180 min, enhanced by Mg++ and Ca++, but inhibited by Zn++, and strongly inhibited by phenylmethylsulfonyl fluoride (PMSF), suggested as serine-protease. The azocasein substrate result showed Km = 0.434 mg/mL and Vmax = 7.739 mg/mL/min. SDS-PAGE and azocasein zymography showed that the purified alkaline protease (2983.8 U/mg) had a molecular mass of 49.3 kDa. The enzyme was purified by column chromatography using Sephadex A50 resin. The proteolytic activity was activated by SDS (sodium dodecyl sulfate), Tween-80, Tween 20 and Triton-100. This study demonstrated that A. tamarii URM4634 protease has potent, stable and compatible collagenolytic activity to the desired level in local laundry detergent brands compared with similar enzymes produced by solid-state fermentation. This protease can thus be chosen as an option in both the food industry to tenderization meat and the detergent industry to washing process.