Juliana dos Santos

Marine-derived fungi: diversity of enzymes and biotechnological applications

The ocean is considered to be a great reservoir of biodiversity. Microbial communities in marine environments are ecologically relevant as intermediaries of energy, and play an important role in nutrient regeneration cycles as decomposers of dead and decaying organic matter. In this sense, marine-derived fungi can be considered as a source of enzymes of industrial and/or environmental interest. Fungal strains isolated from different substrates, such as invertebrates, decaying wood, seawater, sediments, and mangrove detritus, have been reported to be producers of hydrolytic and/or oxidative enzymes, with alginate lyase, amylase, cellulase, chitinase, glucosidase, inulinase, keratinase, ligninase, lipase, nuclease, phytase, protease, and xylanase being among the enzymes produced by fungi of marine origin. These enzymes present temperature and pH optima ranging from 35 to 70∘C, and 3.0 to 11.0, respectively. High-level production in bioreactors is mainly performed using submerged-state fermentation. Certain marine-derived fungal strains present enzymes with alkaline and cold-activity characteristics, and salinity is considered an important condition in screening and production processes. The adaptability of marine-derived fungi to oceanic conditions can be considered an attractive point in the field of fungal marine biotechnology. In this review, we focus on the advances in discovering enzymes from marine-derived fungi and their biotechnological relevance.

Hidrólise da cana-de-açúcar com cal virgem ou cal hidratada

The objective of the present work was to evaluate the effect of the alkaline treatment of sugarcane with virgin lime or hydrated lime on the bromatologic composition and in vitro digestibility of dry matter, neutral detergent fiber, and acid detergent fiber. It was used a complete random design with a 3 × 3 factorial scheme composed by three forms of of sugarcane processing (in natura sugarcane; hydrolyzed sugarcane with 0.5% virgin lime; and hydrolyzed sugarcane with 0.5% hydrated lime) and three storage times (12, 36 and 60 hours). The forms of processing changed the contents of organic matter, mineral matter, total carbohydrates, and hemicellulose as well as the contents of neutral detergent fiber and total digestible nutrients. Times of storage changed contents of crude protein, organic matter, total carbohydrates and hemicellulose. Among the minerals, only content of calcium showed an increase for the sugarcane processing forms. Coeficients of digestibility of dry matter and neutral detergent fiber increased with hydrolises of sugar cane when compared to in natura sugarcane. Hydrolisis with hydrated lime or with virgin lime keeps the nutrional value of sugarcane making its use possible up to 60 hours after storage.

Estabilidade aeróbia, pH e dinâmica de desenvolvimento de microrganismos da cana-de-açúcar in natura hidrolisada com cal virgem

Objetivou-se com este trabalho avaliar o efeito da adicao de cal virgem e dos tempos apos a aplicacao sobre a estabilidade aerobia e o crescimento de microrganismos (leveduras e fungos) na cana-de-acucar in natura. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repeticoes. Avaliaram-se a estabilidade aerobia (temperatura), a dinâmica de desenvolvimento de leveduras e fungos e o pH, em um esquema de parcelas subdivididas, com cinco doses de cal (0; 0,5; 1,0; 1,5 e 2,0%) e cinco tempos apos aplicacao (0, 24, 48, 72, 96 horas). Houve efeito significativo das doses de cal para todos os parâmetros avaliados. A cana que nao foi tratada com cal (0%) apresentou quebra da estabilidade no menor intervalo de tempo. Os valores de pH aumentaram gradativamente de acordo com a dose de cal aplicada e diminuiram com o tempo apos aplicacao. Houve aumento numerico na contagem de leveduras ate as 72 horas apos a aplicacao da cal, independentemente da dose, e os valores tenderam a estabilizar no tempo de 96 horas pos-tratamento. Nao houve efeito significativo das doses de cal sobre o desenvolvimento dos fungos. A aplicacao de cal virgem e eficaz no controle do crescimento de leveduras e aumenta a estabilidade aerobia da cana-de-acucar in natura.

Avaliação da produção de Pleurotus sajor-caju (Fr.) singer utilizando resíduo do beneficiamento têxtil do algodão como substrato

Realizou-se um ensaio objetivando investigar a viabilidade da producao do cogumelo comestivel Pleurotus sajor-caju (Fr.) Singer em substratos cuja principal fonte de carbono fosse o residuo do beneficiamento textil do algodao. Foram avaliadas duas composicoes de substrato: C1 (residuo do beneficiamento textil do algodao, farelo de trigo, gesso e calcario) e C2 (residuo do beneficiamento textil do algodao, farelo de trigo, palha de feijao, gesso e calcario). O experimento foi estabelecido em delineamento inteiramente casualizado, com nove repeticoes por tratamento e os dados de producao e eficiencia biologica foram analisados utilizando-se o procedimento ANOVAG do pacote estatistico SAEG. O residuo do beneficiamento textil do algodao, como principal ingrediente do substrato, mostrou-se eficiente para a producao do cogumelo P. sajor-caju, apresentando valores satisfatorios de produtividade (0,56 e 0,55 kg/kg substrato) e eficiencia biologica (55,76 e 55,39 %), respectivamente para C1 e C2, podendo ser recomendado como alternativa menos onerosa de substrato comercial para a especie Pleurotus sajor-caju.

Cold-adapted enzymes produced by fungi from terrestrial and marine Antarctic environments

Abstract Antarctica is the coldest, windiest, and driest continent on Earth. In this sense, microorganisms that inhabit Antarctica environments have to be adapted to harsh conditions. Fungal strains affiliated with Ascomycota and Basidiomycota phyla have been recovered from terrestrial and marine Antarctic samples. They have been used for the bioprospecting of molecules, such as enzymes. Many reports have shown that these microorganisms produce cold-adapted enzymes at low or mild temperatures, including hydrolases (e.g. α-amylase, cellulase, chitinase, glucosidase, invertase, lipase, pectinase, phytase, protease, subtilase, tannase, and xylanase) and oxidoreductases (laccase and superoxide dismutase). Most of these enzymes are extracellular and their production in the laboratory has been carried out mainly under submerged culture conditions. Several studies showed that the cold-adapted enzymes exhibit a wide range in optimal pH (1.0–9.0) and temperature (10.0–70.0 °C). A myriad of methods have been applied for cold-adapted enzyme purification, resulting in purification factors and yields ranging from 1.70 to 1568.00-fold and 0.60 to 86.20%, respectively. Additionally, some fungal cold-adapted enzymes have been cloned and expressed in host organisms. Considering the enzyme-producing ability of microorganisms and the properties of cold-adapted enzymes, fungi recovered from Antarctic environments could be a prolific genetic resource for biotechnological processes (industrial and environmental) carried out at low or mild temperatures.

Hydrolysis of cane sugar with lime or hydrated lime

The objective of the present work was to evaluate the effect of the alkaline treatment of sugarcane with virgin lime or hydrated lime on the bromatologic composition and in vitro digestibility of dry matter, neutral detergent fiber, and acid detergent fiber. It was used a complete random design with a 3 × 3 factorial scheme composed by three forms of of sugarcane processing (in natura sugarcane; hydrolyzed sugarcane with 0.5% virgin lime; and hydrolyzed sugarcane with 0.5% hydrated lime) and three storage times (12, 36 and 60 hours). The forms of processing changed the contents of organic matter, mineral matter, total carbohydrates, and hemicellulose as well as the contents of neutral detergent fiber and total digestible nutrients. Times of storage changed contents of crude protein, organic matter, total carbohydrates and hemicellulose. Among the minerals, only content of calcium showed an increase for the sugarcane processing forms. Coeficients of digestibility of dry matter and neutral detergent fiber increased with hydrolises of sugar cane when compared to in natura sugarcane. Hydrolisis with hydrated lime or with virgin lime keeps the nutrional value of sugarcane making its use possible up to 60 hours after storage.

Desempenho e características da carcaça de novilhos submetidos à suplementação na seca

Objetivou-se com este trabalho avaliar o efeito de duas estrategias de suplementacao no periodo seco sobre o desempenho e caracteristicas da carcaca de novilhos terminados em capim-marandu. Foram utilizados 36 bovinos Nelore, machos, castrados, com peso inicial de 417 ± 10,7kg e idade media de 20 meses. O delineamento experimental foi inteiramente casualizado com dois tratamentos e dezoito repeticoes. Os tratamentos foram constituidos de sal mineral proteinado (SMP) fornecido ad libitum e da suplementacao com concentrado (SC) com 0,5% do peso corporal (PC). Apos abate, as carcacas foram pesadas, identificadas e resfriadas por 24 horas. Foram medidos rendimento de carcaca, area de olho de lombo, espessura de gordura subcutânea, pH e escore de marmorizacao. Os animais da SC apresentaram maior (P=0,00007) ganho de peso medio diario (0,562kg) e espessura de gordura subcutânea ajustada para 100kg de carcaca (1,7mm) em relacao aos animais do SMP (0,395kg; 1,3mm), respectivamente, mas nao diferiram (P>0,01) em relacao ao peso de carcaca, rendimento de carcaca, area de olho de lombo, pH e marmorizacao. Conclui-se que a suplementacao com concentrado durante o periodo seco proporciona maior ganho de peso medio diario e espessura de gordura subcutânea ajustada para 100kg de carcaca, antecipando a idade de abate e a utilizacao de sal mineral proteinado com massa de forragem adequada pode ser uma alternativa de suplementacao devido menor exigencia de estrutura, controle de consumo, menor mao-de-obra e maior facilidade no fornecimento.