An initial profiling of the intracellular proteome of Aspergillus niger ATCC 10864 biofilm cultures developed on polyester cloth was carried out by using 2D-PAGE and MS-TOF analysis and it was compared to the proteome of conventionally grown free-living submerged cultures. A number of 2D-PAGE protein spots from both types of cultures were subjected to MS-TOF analysis and data interrogation of the NCBI nr database available for this species. Proteomic maps showed different expression patterns in both culture systems with differentially expressed proteins in each case. In biofilm cultures, 19% and 32% of the selected protein spots were over- expressed and differentially expressed, respectively. On the contrary, in free-living cultures, 44% and 7% of the selected protein spots were over-expressed and differentially expressed, respectively. Although preliminary, results presented in this pap...

A preliminary evaluation of transcriptional gene expression in Aspergillus niger ATCC 10864 biofilms developed on polyester cloth was carried out. The expression analysis of genes encoding some lignocellulolytic enzymes and some regulatory genes by means of RT-PCR showed that eng1, eglC, exo, eglA, eglB and xynB genes are differentially expressed in biofilm fermentation either time-related or through the production of more than a transcript as compared to A. niger grown in submerged fermentation. Likewise, the regulatory genes xlnR and creA showed time-related expression patterns that were different in both fermentation systems. Results attained in this work contribute with an initial molecular evidence of differential gene expression as well as differential gene regulation patterns in fungal biofilms that may be related to cell adhesion.

Aspergillus niger biofilms developed on polyester cloth were evaluated considering two aspects related to the growth on surfaces: structure and physiological behavior focused on cellulase production. The biofilm structure was assessed by using electron scanning microphotographs from inoculation and adsorption to 120 h growth. The microphotographs show that biofilm formation can be divided into three phases: 1) Adhesion, which is strongly increased by Aspergillus spore hydrophobicity; 2) Initial growth and development phase from spore germination, that begins 4 to 10 h after inoculation and continues up to 24 h when almost all available surface has been colonized; 3) Maturation phase in which biomass density is highly increased from 48 h after inoculation until 120 h growth when an internal channel organization that assures medium flow through biofilm is clearly evident as it is frequentl...

El Doctor Marcel Gutiérrez-Correa, gran Maestro, reconocido científico, y Padre de la Biotecnología en el País, fue Profesor Principal del Departamento de Biología en la Facultad de Ciencias de la UNALM. Se graduó de Biólogo en la Universidad Nacional Agraria La Molina (UNALM) y obtuvo el grado de Doctor of Philosophy (Ph.D.) en Ciencias Agrícolas-Biotecnología por la Gifu University, Japón. Fue Fundador y Director hasta su partida, del Laboratorio de Micología y Biotecnología de la UNALM, dedicando su vida a la investigación científica durante 41 años ininterrumpidos. Fue Académico de Número en la Academia Nacional de Ciencias. Su excelencia académica y científica es equiparable a su calidad humana y grandeza de espíritu. Valoró su condición de Profesor Universitario, como un Título Nobiliario, al que honró hasta el final de sus días. Este artículo está dedica...

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An initial profiling of the intracellular proteome of Aspergillus niger ATCC 10864 biofilm cultures developed on polyester cloth was carried out by using 2D-PAGE and MS-TOF analysis and it was compared to the proteome of conventionally grown free-living submerged cultures. A number of 2D-PAGE protein spots from both types of cultures were subjected to MS-TOF analysis and data interrogation of the NCBI nr database available for this species. Proteomic maps showed different expression patterns in both culture systems with differentially expressed proteins in each case. In biofilm cultures, 19% and 32% of the selected protein spots were over- expressed and differentially expressed, respectively. On the contrary, in free-living cultures, 44% and 7% of the selected protein spots were over-expressed and differentially expressed, respectively. Although preliminary, results presented in this pap...

Se realizó una evaluación génica preliminar a nivel transcripcional de biopelículas de Aspergillus niger ATCC 10864 desarrolladas sobre poliéster respecto a algunas enzimas lignocelulolíticas. El análisis de expresión de genes de enzimas lignocelulolíticas y genes reguladores mediante RT-PCR mostró que los genes eng1, eglC, exo y eglA, eglB y xynB son diferencialmente expresados ya sea temporalmente o mediante más de un transcripto en comparación con cultivos sumergidos. Asimismo, los genes reguladores xlnR y creA mostraron patrones temporales de expresión distintos en ambos sistemas. Los resultados obtenidos aportan la evidencia molecular inicial de expresión diferencial de genes en biopelículas así como patrones de regulación diferencial muy probablemente ligada a la adhesión celular.

Aspergillus niger biofilms developed on polyester cloth were evaluated considering two aspects related to the growth on surfaces: structure and physiological behavior focused on cellulase production. The biofilm structure was assessed by using electron scanning microphotographs from inoculation and adsorption to 120 h growth. The microphotographs show that biofilm formation can be divided into three phases: 1) Adhesion, which is strongly increased by Aspergillus spore hydrophobicity; 2) Initial growth and development phase from spore germination, that begins 4 to 10 h after inoculation and continues up to 24 h when almost all available surface has been colonized; 3) Maturation phase in which biomass density is highly increased from 48 h after inoculation until 120 h growth when an internal channel organization that assures medium flow through biofilm is clearly evident as it is frequentl...

El Doctor Marcel Gutiérrez-Correa, gran Maestro, reconocido científico, y Padre de la Biotecnología en el País, fue Profesor Principal del Departamento de Biología en la Facultad de Ciencias de la UNALM. Se graduó de Biólogo en la Universidad Nacional Agraria La Molina (UNALM) y obtuvo el grado de Doctor of Philosophy (Ph.D.) en Ciencias Agrícolas-Biotecnología por la Gifu University, Japón. Fue Fundador y Director hasta su partida, del Laboratorio de Micología y Biotecnología de la UNALM, dedicando su vida a la investigación científica durante 41 años ininterrumpidos. Fue Académico de Número en la Academia Nacional de Ciencias. Su excelencia académica y científica es equiparable a su calidad humana y grandeza de espíritu. Valoró su condición de Profesor Universitario, como un Título Nobiliario, al que honró hasta el final de sus días. Este artículo está dedica...

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Basic knowledge on solid state fermentation and on biofilm formation is summarized and related to cell adhesion processes. These subjects are covered from the engineering and molecular biology points of view. Contrary to the common believe, the advantages of solid state fermentation are related to the adhesion of fungi to solid particles instead of being due to the low water content. Thus, solid state fermentation and biofilm fermentation (erroneously known as adsorption immobilization) are technical variants of the same biological process, and should be referred as Surface Adhesion Fermentation.

Basic knowledge on solid state fermentation and on biofilm formation is summarized and related to cell adhesion processes. These subjects are covered from the engineering and molecular biology points of view. Contrary to the common believe, the advantages of solid state fermentation are related to the adhesion of fungi to solid particles instead of being due to the low water content. Thus, solid state fermentation and biofilm fermentation (erroneously known as adsorption immobilization) are technical variants of the same biological process, and should be referred as Surface Adhesion Fermentation.

The antioxidant activities of the aqueous extracts of seven wild plants were investigated, using both in vitro and in vivo assays. The former relied on the use of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the latter, on the sensibility towards hydrogen peroxide of the yeast sod1 mutant. The studied plants were all wild, collected at the Ccamarrara hill (4000 m.a.s.l. Cusco, Peru), and of the following species: Plantago australis, Baccharis latifolia, Ageratina sternbergiana, Stevia macbridei, Ageratina cuzcoensis, Calceolaria myriophylla, and Adiantum orbignyanum. The DPPH assay demonstrated high antioxidant contents in the dry leaves of all tested plants, with AAEAC values (ascorbic acid equivalent antioxidant capacity) ranging from 20.6 to 72.7 mg/g dry leaves. The antioxidant activities were also evident in the yeast assay, which also allowed distinction between the intracellular and e...

Cloning and protein expression in heterologous systems are very useful tools for the study of viral proteins. In this work, an in vivo cloning strategy was applied using the yeast Saccharomyces cerevisiae, as an efficient and low-cost method to clone several cDNAs from the tilapia lake virus (TiLV). Samples of infected tilapia Oreochromis niloticus tissues were taken and used to isolate their RNA and to obtain and clone the ten viral cDNAs in a shuttle plasmid. The cloning efficiencies range from 5 to 100% but for seven of the cDNAs the values were above 40%, demonstrating the high efficiency of the method. © 2021 The Authors. Journal of the World Aquaculture Society published by Wiley Periodicals LLC on behalf of World Aquaculture Society.

Aims: To isolate and characterize lignocellulase producing thermophilic bacteria from a Peruvian hot spring. Study Design: Combined sediment and water samples from the hot spring were subjected to direct plating, in situ baiting and ex situ enrichment. Endoglucanase and xylanase producing bacterial colonies were isolated and characterized. Place and Duration of Study: Samples were taken from the Huancarhuaz hot spring, Peru (8º56’31.86”S, 77º47’00.53”W) in August 2010 and processed during 2011-2013. Methodology: Samples were subjected to three isolation methods and bacterial colonies with different color, size and appearance, were isolated, purified by streaking several times and conserved in Tryptic Soy Agar slants at 4ºC. The agar staining method was used to isolate enzyme-producing strains which were then identified by 16S rRNA sequencing and further studied for endoglucana...

It was isolated bacteria strains from three different types of samples: fresh water, in situ baits and ex situ enrichment. Serial dilutions were prepared and culture was carried at 50 °C using a Basal-Saline medium. Isolated strains were screened for endoglucanase and xylanase activities with qualitative (Congo Red) and quantitative (DNS) methods. Molecular 16S rDNA sequencing analysis was performed for taxonomic identification. It was isolated 31 strains of which 14 showed hydrolytic activities and belonged to Bacillus subtilis and Bacillus licheniformis species. Moreover, the strain B. subtilis DCH4 showed the highest endoglucanase activity at 45°C and pH 5, and xylanase activity at 55°C and pH 6. Then, DCH4 was cultivated by submerged fermentation with two different media supplemented with sugar cane bagasse, wheat straw, or quinoa stalk to evaluate its saccharification capability....

It was isolated bacteria strains from three different types of samples: fresh water, in situ baits and ex situ enrichment. Serial dilutions were prepared and culture was carried at 50 °C using a Basal-Saline medium. Isolated strains were screened for endoglucanase and xylanase activities with qualitative (Congo Red) and quantitative (DNS) methods. Molecular 16S rDNA sequencing analysis was performed for taxonomic identification. It was isolated 31 strains of which 14 showed hydrolytic activities and belonged to Bacillus subtilis and Bacillus licheniformis species. Moreover, the strain B. subtilis DCH4 showed the highest endoglucanase activity at 45°C and pH 5, and xylanase activity at 55°C and pH 6. Then, DCH4 was cultivated by submerged fermentation with two different media supplemented with sugar cane bagasse, wheat straw, or quinoa stalk to evaluate its saccharification capability....

Production of lignocellulolytic enzymes by filamentous fungi have a great potential at industrial level due to their widespread applications. Mixed fungal cultures and particularly mixed fungal biofilms constitute a promising fermentation system for an enhanced enzyme production. However, it has not been addressed how much of this enhancement depends on the mixed biomass proportion. In this sense, the aim of this study was to develop a method to specifically and accurately quantify mixed fungal biomass. For this purpose, mixed biofilm cultures composed of Aspergillus niger and Trichoderma reesei, two filamentous fungi used industrially for cellulase production, were collected from 48 to 120 h of growth; mycelia were pulverized, and DNA was extracted for qPCR assays with specific primers for each fungus. Primers were designed from non-conserved regions of sequences of actin and β-tubulin...