In this paper, I make a historical account of the fifty years that have the degree in biology at the Universidad Nacional Agraria La Molina and gestation, and the beginning, development and maturation of biotechnology in this university. We describe some details of the three most important curricular modifications that led to the establishment of the biotechnology area in the curricula of undergraduate and doctoral programs, as well as their main achievements. The development of biotechnology at the UNALM has influenced the development of this area in Peru not only in the curricular changes that have occurred in several Peruvian universities, but also in the biotechnology research being carried out in many regions of the country. In this historical process, I conclude that the balance is positive and that the best epistemology stream is that which leads through research to find truths us...

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.

Se realiza un relato histórico sobre los cincuenta años que tiene la carrera de biología en la Universidad Na-cional Agraria La Molina y la gestación, inicio, desarrollo y maduración de la biotecnología en esta universidad. Se describen algunos pormenores de las tres grandes estructuraciones curriculares que finalmente derivan al establecimiento del área de biotecnología en el pregrado y en el doctorado así como a los logros alcanzados. El desarrollo de la biotecnología en la UNALM ha influenciado el desarrollo de esta área en el Perú no solo en las adaptaciones curriculares que se han producido en varias universidades del país sino también en las investigaciones biotecnológicas que se llevan a cabo en universidades e institutos de investigación en las diferentes regiones del país. En este devenir histórico se concluye que el balance es muy positivo y que la mejor corri...

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.

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...

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...

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.

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.

Para el establecimiento del cultivo in ,·itro de yemas de Perezio coerulescens Wedd, se evaluaron seis métodos de desinfección usando hipoclorito de sodio (NaOCI) y clicloruro de mercurio (l--- lgCl2 ) a diferentes concentraciones y tiempos; se evaluó el porcentaje de contaminación, supervivencia y fenolización de las yemas. El establecimiento se realizó en medio Murashige y Skoog a la mitad de concentración de sales suplementado con sacarosa (2%), agar-agar (0,75%), un fotoperíodo de 16 horas y temperatura ambiental ( 16 - 20 ºC). Para la multiplicación se probó cuatro tratamientos, usando bencil amino purina (BAP) y ácido naftalén acético (ANA): TO-S4 (sin hormona), TJ-S4 (1 mgL· 1 de BAP y 0,01 mgL·1 ele ANA), T2-S4 ( 1 mgL· 1 de BAP), T3-S4 (2 mgL· 1 de BAP y 0,02 mgL" de ANA). Se encontró que el mejor tratamiento de desinfección fue con HgCl2 al O, 1 % (p/v) por...

Para el establecimiento del cultivo in ,·itro de yemas de Perezio coerulescens Wedd, se evaluaron seis métodos de desinfección usando hipoclorito de sodio (NaOCI) y clicloruro de mercurio (l--- lgCl2 ) a diferentes concentraciones y tiempos; se evaluó el porcentaje de contaminación, supervivencia y fenolización de las yemas. El establecimiento se realizó en medio Murashige y Skoog a la mitad de concentración de sales suplementado con sacarosa (2%), agar-agar (0,75%), un fotoperíodo de 16 horas y temperatura ambiental ( 16 - 20 ºC). Para la multiplicación se probó cuatro tratamientos, usando bencil amino purina (BAP) y ácido naftalén acético (ANA): TO-S4 (sin hormona), TJ-S4 (1 mgL· 1 de BAP y 0,01 mgL·1 ele ANA), T2-S4 ( 1 mgL· 1 de BAP), T3-S4 (2 mgL· 1 de BAP y 0,02 mgL" de ANA). Se encontró que el mejor tratamiento de desinfección fue con HgCl2 al O, 1 % (p/v) por...

Para el establecimiento del cultivo in ,·itro de yemas de Perezio coerulescens Wedd, se evaluaron seis métodos de desinfección usando hipoclorito de sodio (NaOCI) y clicloruro de mercurio (l--- lgCl2 ) a diferentes concentraciones y tiempos; se evaluó el porcentaje de contaminación, supervivencia y fenolización de las yemas. El establecimiento se realizó en medio Murashige y Skoog a la mitad de concentración de sales suplementado con sacarosa (2%), agar-agar (0,75%), un fotoperíodo de 16 horas y temperatura ambiental ( 16 - 20 ºC). Para la multiplicación se probó cuatro tratamientos, usando bencil amino purina (BAP) y ácido naftalén acético (ANA): TO-S4 (sin hormona), TJ-S4 (1 mgL· 1 de BAP y 0,01 mgL·1 ele ANA), T2-S4 ( 1 mgL· 1 de BAP), T3-S4 (2 mgL· 1 de BAP y 0,02 mgL" de ANA). Se encontró que el mejor tratamiento de desinfección fue con HgCl2 al O, 1 % (p/v) por...

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...

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...

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...