Abstract The use of biodegradable polymers arouses biotechnological interest. This use allows applications in health and environment. Here is present the characterization and a proposition for the use of cashew (Anacardium othonianum Rizz.) polysaccharide including peroxidase immobilization for wastewater bioremediation. From the cashew gum exudate, the polysaccharide was extracted by precipitation in ethanol at 4 °C. This material is able to immobilize Horseradish peroxidase by physical adsorption and via sodium periodate with 75% and 93% of efficiency, respectively. These systems have a storage and operational stability, and removed phenolic compounds above 50% in industrial effluent samples. The bioassays in the presence of Artemia salina and Allium cepa root not only revealed no toxicity to this polysaccharide, but also presented the ability to reduce the toxicity of the industrial effluent by 50%. Immobilized cashew polysaccharide complexes are potential alternatives for waste treatment and decontaminant agents for water treatment applications. The polysaccharide is a low-cost natural matrix for environmental-technological applications.

Resumo Os compostos fenólicos ocorrem em efluentes de uma grande variedade de processos industriais e apresentam toxicidade e geram problemas ambientais. O tratamento desses resíduos via imobilização de enzimas indica que a peroxidase (EC 1.11.1.7) é a enzima mais utilizada. Nos mesmos processos, polímeros biodegradáveis têm gerado grande interesse para a comunidade científica e industrial. Neste trabalho os biopolímeros de bagaço de cana-de-açúcar (BC) e o polissacarídeo de caju arbóreo do Cerrado (PEJU-GO) foram utilizados como suportes para imobilização de peroxidase de extrato bruto de abobrinha verde via adsorção física e ligação covalente. Além disso, usamos esses sistemas para a remoção de fenóis de efluentes industriais. A microscopia eletrônica mostrou que BC possui uma superfície fibrosa e que PEJU-GO apresentou-se como material microporoso, características que facilitam processos de imobilização. Os espectros de infravermelho de ambos materiais elucidaram bandas características de açúcares. Para a estabilidade operacional após 30 dias de armazenamento a peroxidase imobilizada reteve 69 e 50% de atividade para BC e PEJU-GO, respectivamente. Os sistemas foram capazes de remover até 79% de compostos fenólicos de efluentes industriais. Assim sendo, os biopolímeros de bagaço de cana-de-açúcar e do polissacarídeo de caju arbóreo do Cerrado são fontes promissoras para a biotecnologia, especialmente para a imobilização de peroxidase. Isto irá proporcionar a imobilização enzimática na prática laboratorial, com comportamento estável em diferentes condições de pH, a custo baixo, sendo um material biodegradável, não-tóxico e extraído de forma sustentável.

Abstract Phenolic compounds occur in effluents from a wide variety of industrial operations, and they present toxicity and generate environmental problems. The treatment of these wastes via enzyme immobilization indicates that peroxidase (E.C.1.11.1.7) is the enzyme with the widest application. In the same process, biodegradable polymers have generated significant interest from research and industrial communities. Here we applied biopolymers from sugarcane bagasse (SB) and Cerrado cashew-tree polysaccharide (PEJU-GO) as supports for peroxidase immobilization from crude green zucchini extract via physical adsorption and covalent bonding. In addition, we used these systems in the removal of phenols from industrial effluents. Electron microscopy showed a fibrous surface for SB and a microporous material for PEJU-GO, characteristics that facilitate the immobilization. The infrared of both materials elucidated characteristic bands of sugars. For operational stability after 30 days of storage, the immobilized peroxidase retained 69 and 50% activity for SB and PEJU-GO, respectively. The systems were able to remove up to 79% of phenolics from industrial wastes. Therefore, the biopolymers from sugarcane bagasse and cashew-tree polysaccharide are promising sources for biotechnology, especially when used for peroxidase immobilization. This will support enzymatic activity in laboratory practice, with homogeneous behavior in different pH conditions, at low cost, biodegradable, non-toxic and extracted in a sustainable way.