Cold-active pectinolytic activity produced by filamentous fungi associated with Antarctic marine sponges

BACKGROUND: Pectinase enzymes catalyze the breakdown of pectin, a key component of the plant cell wall. At industrial level, pectinases are used in diverse applications, especially in food-processing industry. Currently, most of the industrial pectinases have optimal activity at mesophilic temperatures. On the contrary, very little is known about the pectinolytic activities from organisms from cold climates such as Antarctica. In this work, 27 filamentous fungi isolated from marine sponges collected in King George Island, Antarctica, were screened as new source of cold-active pectinases. RESULTS: In semi-quantitative plate assays, 8 out 27 of these isolates showed pectinolytic activities at 15 °C and one of them, Geomyces sp. strain F09-T3-2, showed the highest production of pectinases in liquid medium containing pectin as sole carbon source. More interesting, Geomyces sp. F09-T3-2 showed optimal pectinolytic activity at 30 °C, 10 °C under the temperature of currently available commercial mesophilic pectinases. CONCLUSION: Filamentous fungi associated with Antarctic marine sponges are a promising source of pectinolytic activity. In particular, pectinases from Geomyces sp. F09-T3-2 may be potentially suitable for biotechnological applications needing cold-active pectinases. To the best of our knowledge, this is the first report describing the production of pectinolytic activity from filamentous fungi from any environment in Antarctica.

Improvement of Bacillus strains by mutation for overproduction of exopolygalacturonases.

Pectinases, produced by microorganisms, have wide range application in food industry, textile processing, paper making, coffee and tea fermentation, etc. It accounts for 10% of the global industrial enzymes produced. The most important and widely used commercial pectinase polygalacturonase is produced by alkalophilic strains of Bacillus sp. and Streptomyces sp. Here, we explored 29 bacterial strains isolated from rotten mango samples for polygalacturonase production and selected 16 strains through preliminary screening by well-plate method for enzyme activity. The maximum zone of inhibition of pectin was observed up to 28 mm in diameter but one strain ZM11 was exhibiting no activity. Quantitative dinitrisalicylic acid (DNS) assay for polygalacturonase enzyme was also performed for the selected bacterial isolates. All the strains bestowed significant enzyme activity with the highest activity of 2.4 U/µL exhibited by strain ZM3 (P ≤0.05). Characterization of the isolates was performed using different biochemical tests which also confirmed the isolates as members of the genus Bacillus. Mutation was induced to the selected strains by UV light and acridine orange for different periods of time. Qualitative and quantitative assays of the mutant bacterial isolates showed that the enzyme activity increased to 4.62 U/µL which clearly indicated that induced mutation enhanced the ability of Bacillus strains to produce more polygalacturonase enzyme up to 3-fold as compared to the wild strains (P ≤0.05). Molecular characterization by 16S rRNA sequences further confirmed that the bacterial isolates belong to Bacillus subtilis and B. amyloliquefaciens.

Enhanced production of pectinolytic enzymes from immobilized cells of mixed aspergillus species.

The cells of isolated mixed culture of Aspergillus fumigatus and Aspergillus sydowii were immobilized in calcium alginate beads. Studies were carried out on different parameters like alginate concentration, incubation time and bead inoculum which affects the productivity and stability of the immobilized system. The best enzymatic activities were obtained with 3% alginate concentration, 48h of incubation time and 200 beads/flask of inoculum. Optimization of these factors causes an increase in enzymatic activities and the possibility of semicontinuous cultivation. Immobilized cells could be reused in five successive reaction cycles with a slight decrease in activities.

Evaluación de actividades enzimáticas de Fusarium spp., aislados de lesiones en humanos, animales y plantas / Avaliação das atividades enzimáticas de Fusarium spp. Isolados a partir de lesões em humanos, animais e plantas / Assessment of enzymatic characterization of Fusarium spp. isolated from human, animal, and plant rounds

Objetivo. Determinar actividades amilolíticas, celulolíticas, lipolíticas, pectinolíticas y proteolíticas en 32 aislamientos de Fusarium spp. de origen humano, animal y vegetal. Materiales y métodos. Las actividades enzimáticas se determinaron a nivel cualitativo, por medio de la medición de halos de hidrólisis en placas de agar con el respectivo sustrato, y a nivel cuantitativo se realizó un cultivo líquido para determinar la degradación del respectivo sustrato por medio de técnicas colorimétricas. Resultados. Todos los aislamientos presentaron actividades enzimáticas a nivel cualitativo, excepto las amilolíticas y lipolíticas. La determinación a nivel cuantitativo fue posible para las enzimas evaluadas, a excepción de las lipasas. Conclusión. La determinación de los perfiles enzimáticos amilolíticos, celulolíticos, pectinolíticos y proteolíticos de cada uno de los aislamientos evaluados pertenecientes al género Fusarium sugirió su capacidad, indistintamente de su procedencia, de degradar estos sustratos...

Assessment of enzymatic characterization of Fusarium spp. isolated from human, animal, and plant wounds. Objective. To determine amylolytic, cellulolytic, lipolytic, pectinolytic and proteolytic activities in 32 Fusarium spp. isolates from humans, animals and plants. Materials and methods. Qualitative determination of enzymatic activities was done by measuring hydrolysis halos in agar plates with their corresponding substrate. Quantitative determination was done by colorimetric techniques, using liquid culture supernatants to determine the respective substrate degradation. Results. All isolates showed enzymatic activities from a qualitative point of view, except amylolytic and lipolytic. Quantitative determination was possible for all the evaluated enzymes except lipases. Conclusion. The determination of amylolytic, cellulolytic, pectinolytic and proteolytic enzymatic profiles of each of the Fusarium isolates assessed suggests their capacity to degrade these substrates, irrespectively of their origin...

Avaliação das atividades enzimáticas de Fusarium spp. Isolados a partir de lesões em humanos, animais e plantas. Objetivo. Determinar as atividades amilolíticas, celulolíticas, lipolítica, pectinolíticas e proteolíticas em 32 isolamentos de Fusarium spp. de origem humana, animal e vegetal. Materiais e métodos. As atividades enzimáticas foram determinadas a nível qualitativo medindo os halos de hidrólise em placas de agar com o substrato respectivo e a nível quantitativo realizou-se uma cultura líquida para determinar a degradação do substrato respectivos por meio de técnicas colorimétricas. Resultados. Todos os isolados apresentaram uma atividade enzimática a nível qualitativo, exceto as amilolíticas e lipolíticas. A determinação a nível quantitativo foi possível para as enzimas testadas, exceto para as lipases. Conclusão. A determinação de perfis enzimáticos amilolíticos, celulolíticos, pectinolíticos e proteolíticos de cada um dos isolados testados pertencentes ao gênero Fusarium, sugeriu sua capacidade, independentemente da sua origem, para degradar estes substratos...

Extracellular enzymes of Fusarium graminearum isolates

Fusarium graminearum isolates from three different agroecological regions in Argentina were examined according to the production of different extracellular enzyme activities of potential biotechnological interest: pectinases (PGase: polygalacturonase and PMGase: polymethylgalacturonase), cellulase (CMCase: carboxymethylcellulase) and hemicellulase (xylanase). The isolates were grown in minimum salt medium supplemented with 0.25 percent glucose, 0.125 percent citric pectin and 0.125 percent oat bran as carbon sources and/or enzyme inducers. PGase activity was detected early (after two days of incubation) in all the cultures; it was found to be the highest for all the isolates. PMGase was high only for those isolates of the II region. CMCase and endoxylanase activities were particularly found at late stages (after four and seven days of incubation, respectively) and the maximum values were lower than pectinase activities.

Production of pectinases by A. niger: influence of fermentation conditions

Response surface methodology was used for optimization of polygalacturonase (PG) and pectinesterase (PE) production in submerged fermentation by A.niger. A Central Composite Experimental Design was applied, consisting of 22 experiments, including eight central points. Variables studied were: fermentation time (24 to 120 h), pH (3.5 to 6.5) and initial concentration of pectin (5 to 20 g/l). Maximum PE production was 220 U/l, after 74 h of culture, in a medium containing 20 g/l of pectin (pH 6.5). The optimal conditions for PG production were pH: 4.1, 20 g/l of pectin and 94 h of fermentation with a maximum value of 1032 U/l. Under these conditions, the PE production was low (15 U/l). A liquid extract with high PG activity and low PE activity could be suitable to be used in food processing in order to reduce the production of methanol.

A metodologia de superfície de resposta foi utilizada para a otimização da produção de poligalacturonasa (PG) e pectinesterasa (PE), por A. niger em fermentação submergida. Foi aplicado um Desenho Experimental Composto Central abrangendo 22 experiências, incluindo oito pontos centrais. As variáveis estudadas foram: tempo de fermentação (24 a 120 h), pH (3.5 a 6.5) e concentração inicial de pectina (5 a 20 g/l). A produção máxima de PE foi de 220 U/l, após 74h de cultivo, 20 g/l de pectina e pH 6.5. As condições ótimas para a produção de PG foram pH 4.1, 20 g/l de pectina e 94 h de fermentação, com um valor máximo de 1032 U/l. Sob estas condições, a produção de PE foi baixa (15 U/l). Um extrato líquido com alta atividade PG e baixa atividade PE poderia ser conveniente para ser utilizado no processamento e alimentos, visando reduzir a produção de metanol.