Lentinus crinitus response to blue light on carbohydrate-active enzymes / Resposta de Lentinus crinitus à luz azul em enzimas ativas por carboidratos

Fungi are capable of sensing light from ultraviolet to far-red and they use light as a source of information about the environment anticipating stress and adverse conditions. Lentinus crinitus is a lignin-degrading fungus which produces laccase and other enzymes of biotechnological interest. The effect of blue light on fungal enzymatic activity has been studied; however, it has not been found studies on the effect of the blue light on carbohydrate-active enzymes and on mycelial biomass production of L. crinitus. We aimed to investigate carbohydrate-active enzymes activity and mycelial biomass production of L. crinitus cultivated under continuous illumination with blue light. L. crinitus was cultivated in malt extract medium in the dark, without agitation, and under continuous illumination with blue light-emitting diodes. The blue light reduced the total cellulase, pectinase and xylanase activities but increased the endoglucanase activity. Blue light reduced the mycelial growth of L. crinitus in 26% and the enzymatic activity-to-mycelial biomass ratio (U mg-1 dry basis) increased in 10% total cellulase, 33% endoglucanase, and 16% pectinase activities. Also, it is suggested that L. crinitus has a photosensory system and it could lead to new process of obtaining enzymes of biotechnological interest.

Fungos são capazes de sentir a luz com comprimentos de onda que variam do ultravioleta ao infravermelho e usam a luz como fonte de informação sobre o ambiente, antecipando condições adversas e de estresse. Lentinus crinitus é um fungo ligninolítico que produz lacase e outras enzimas de interesse biotecnológico. O efeito da luz azul na atividade enzimática de fungos já foi estudado, contudo, ainda não há estudos sobre o efeito da luz azul na produção de enzimas ativas sobre carboidratos (CAZymes, carbohydrate-active enzymes) e de biomassa micelial de L. crinitus. O objetivo deste estudo foi investigar a avitivade de CAZymes e a produção de biomassa micelial de L. crinitus cultivado sob iluminação continua com luz azul. L. crinitus foi cultivado em meio extrato de malte, sem agitação, na ausência de luz e sob luz continua fornecida por diodos emissores de luz azul. A luz azul reduziu a atividade de cellulase total, pectinase e xilanase, mas aumentou a atividade de endoglucanase. A luz azul reduziu o crescimento micelial de L. crinitus em 26% e aumentou a razão atividade enzimática/biomassa micelial (U mg-1 em base seca) de cellulase total em 10%, endoglucanase em 33% e pectinase em 16%. Além disso, sugere-se que L. crinitus possua um sistema fotossensorial que poderia ser explorado para a otimização de bioprocessos que visam a obtenção de enzimas de interesse biotecnológico.

Characterization of cellulase, hemicellulase and lipase and its use in deinking of laser printed paper

Aims: It is recognized that laser printed paper are difficult to deink using conventional method. This had lead to the suggestion of enzymatic approach to overcome the problem encountered by commonly employed deinking techniques. The present study aimed to investigate 7 commercially available enzymes for their suitability use in deinking of laser printed paper. Methodology and results: 3 cellulases, hemicellulases, xylanase and 2 lipases were used in enzymatic deinking of laser-printed wastepaper. Cellulase A “Amano”3 (C), Hemicellulase (H) and lipase (L) were selected for used in deinking because they possess either highest activity or broad pH stability compared to others enzymes. Different combination of enzymes was carried out to evaluate their effectiveness in deinking process. CH enzymes sequence was determined to be the most effective sequence in toner removal with 1.90% of brightness increment. However, only 0.95% of brightness increment was gained by enzyme sequence L. Highest deinking efficiency obtained was not proportional to the highest total reducing sugar produced. Conclusion, significance and impact of study: Enzyme (cellulase and hemicellulase) can be used to de-ink laserprinted wastepaper, which are difficult to be deinked by conventional chemical deinking process. Thus, enzyme deinking has high possibility as alternative method to current chemical deinking process which is not environmental friendly.

Improvement of Transformation System in Filamentous Fungus Aspergillus oryzae / 대한의진균학회지

Aspergillus oryzae is a filamentous fungus classified in the group Aspergillaceae Ascomycetes. A. oryzae is an important microorganism for industrial production of enzymes and fermented food products. It secrets large quantities of proteins or enzymes into the culture medium which makes this organism appealing for the production of heterologous proteins. Recently Electric field-mediated transformation method, electroporation, has been applied to fungal transformation. It is fast, simple to handle, and avoids the use of some chemicals. The optimum conditions for A. oryzae were determined with pILJ-16 and ~0.2 x 105 protoplast cell at various field strength. The survived population of protoplasts in the electric field were ~80% of nonprotoplast cell population at 1.3 KV/cm to ~50% at 6.3 KV/cm. The electrotransformation efficiency, expressed as transformants/microgram of input DNA/population of protoplast cells, increased with the increment of the field strength up to 6.3 KV/cm. The highest value, 14.35%, was obtained at 6.3 KV/cm and 1540ohm. Some antibiotics for the dominant selectable makers were applied to A. oryzae and Tolypocladium inflatum. Whereas phleomycin was very effective on T. inflatum, hygromycin B and phleomycin were not effective on A. oryzae. Protoplasts were obtained with hemicellulase and celluclast, instead of novozyme234. More than 104 transformants/microgram of DNA with hemicellulase-treated protoplasts were obtained by using electroporation at the condition of 2,500 voltage, 1,540 ohm and 0.50 capacitance. Less than 102 transformants/microgram of DNA were obtained with Novozyme234- and celluclast-treated protoplasts.

Expression Characteristics of Enzyme Activity of a Multi-functional Bacterial Community NSC-7 / 微生物学通报

In order to determine the degradation activity of the microbial community NSC-7, which had effi- cient cellulose and lindan degrading ability, degrading ability and four kinds of cellulase activity and hemi- cellulase activity were detected during degradation progress. The results showed that NSC-7 could degrade 73.6% of rice staw in weight, including 82.1% of cellulose, 58.2% of hemicellulase, and 5.4% of lignin within fourteen days. Endoglucanases, exoglucanases, ?-glucosidases and the total cellulase activities reached to maximum at the eighth day, and they were 4.48 U/mL, 15.83 U/mL, 25.78 U/mL and 7.51U /mL, respectively. The maximum of hemicellulase activity was 280.6 U/mL at the fifth day, and the average of hemicellulase activity was 43.71 times higher than cellulase activity.