Fibrolytic activity of four Trichoderma strains grown on agro-industrial residues

The aim of this study was to compare the cellulolytic and xylanolytic activities of two strains of Trichoderma viride, one of Trichoderma reesei and one of Trichoderma harzianum grown on four different substrates. Each substrate contained 20% wheat bran and 80% agro-industrial waste (corn stover (CS), sugarcane bagasse (SCB), Yucca schidigera fiber (YS), or compost elaborated from solid waste generated in the university cafeteria (CSW)). An interaction (P < 0.01) between the substrate and strain was detected for both cellulolytic and xylanolytic enzyme activities. The highest cellulolytic activity (P < 0.01) was obtained with T. reesei grown on YS, CS, and SBC, and the lowest was from the two T. viride strains grown on most of the substrates. The highest xylanolytic activities (P < 0.01) were detected for T. harzianum with YS and SCB and T. reesei with CSW and CS, while one T. viride strain exhibited intermediate and the other showed the lowest activity. In conclusion, T. reesei CDBB356 showed the highest fibrolytic activity for most of the tested substrates, a finding that suggests it has the highest potential for fibrolytic enzyme production. There is a potential application for T. reesei CDBB356 enzymes on ruminant feed supplements to improve forage digestibility.The aim of this study was to compare the cellulolytic and xylanolytic activities of two strains of Trichoderma viride, one of Trichoderma reesei and one of Trichoderma harzianum grown on four different substrates. Each substrate contained 20% wheat bran and 80% agro-industrial waste (corn stover (CS), sugarcane bagasse (SCB), Yucca schidigera fiber (YS), or compost elaborated from solid waste generated in the university cafeteria (CSW)). An interaction (P < 0.01) between the substrate and strain was detected for both cellulolytic and xylanolytic enzyme activities. The highest cellulolytic activity (P < 0.01) was obtained with T. reesei grown on YS, CS, and SBC, and the lowest was from the two T. viride strains grown on most of the substrates. The highest xylanolytic activities (P < 0.01) were detected for T. harzianum with YS and SCB and T. reesei with CSW and CS, while one T. viride strain exhibited intermediate and the other showed the lowest activity. In conclusion, T. reesei CDBB356 showed the highest fibrolytic activity for most of the tested substrates, a finding that suggests it has the highest potential for fibrolytic enzyme production. There is a potential application for T. reesei CDBB356 enzymes on ruminant feed supplements to improve forage digestibility

Effect of a Fibrolytic Enzymatic Extract from Cellulomonas flavigena on In Vitro Degradation and In Vivo Digestibility and Productive Performance of Lambs

An enzymatic extract from Cellulomonas flavigena was evaluated at 0, 2.5, 7.5, 12.5 mL/kg DM of total mixed ration (TMR) on the in vitro degradation of DM, NDF and ADF and in vivo at 0, 5.0 and 7.5 mL of extract per kg DM of TMR to determine the digestibility and productive performance of lambs fed a TMR made up of 60% forage. Twenty four Pelibuey-Kathadin lambs were used in the trial. The in vitro degradation of ADF showed a linear (P<0.05) response from 6 to 72 h. There was no effect on DM intake, daily gain or feed conversion. The enzymatic dose tended to linearly decrease the apparent digestibility of DM (P=0.06), NDF (P=0.10) and ADF (P=0.06). The N-NH3 concentration showed a linear decrease (P=0.002) and total VFA concentration was linearly (P<0.001) increased. The incorporation of extract of Cellulomonas flavigena in the diet increased in vitro degradation of cellulose in terms of ADF but did not increase the digestion or productive performance of lambs

Fungal Invertase Expression in Solid-State Fermentation

U ovom je istraživanju ocijenjena ekspresija aktivnosti invertaze u soju plijesni Aspergillus niger Aa-20 pri različitim koncentracijama dvaju supstrata tijekom rasta na čvrstoj podlozi od poliuretanske pjene. Kao represor upotrijebljena je glukoza, a kao induktor saharoza. Proizvodnja invertaze povećala se dodatkom do 100 g glukoze na litru podloge, a pri većim koncentracijama se smanjila. Omjer indukcije i represije pri svim koncentracijama glukoze bio je 2,5 puta veci od onog pri osnovnim uvjetima (bez induktora).In this study invertase activity expression in Aspergillus niger Aa-20 was evaluated under different concentrations of two substrates using solid-state fermentation (SSF) on polyurethane foam. Glucose was used as repressor and sucrose was the inducer. Invertase production increased when glucose was present in the medium (up to 100 g/L); however, higher concentration than this reduced the enzyme production. Induction-repression ratio obtained using any glucose concentration was at least 2.5 times higher than that under basal conditions (without inducer)

Experiencia de caries dental en trabajadores universitarios: su asociación con variables sociodemográficas

Objetivo. Evaluar la experiencia de caries en trabajadores universitarios y su asociación con variables sociodemográficos.&nbsp;Métodos. Estudio transversal, observacional y analítico con un grupo de trabajadores de la Universidad de Guadalajara, México. Se recopilaron datos de las variables sociodemográficas mediante un cuestionario y a través del examen clínico el índice CPOD. Se realizaron pruebas estadísticas de Chi-cuadrado, t-Student, ANOVA de una vía y post-hoc con significancia de 0,05. Resultados. Doscientos noventa participantes accedieron a la exploración oral, con un promedio de edad de 36,2 ± 0,6, 55,9% fueron mujeres. El CPOD de la muestra evaluada fue de 8,3±5,3. El análisis de Chi-cuadrado en la evaluación etaria y los niveles de CPOD mostraron significancia estadística (p=0,0001). De forma similar, en las pruebas de ANOVA de una vía en el grupo de hombres (p=0,0001) y en los que residen en Tonalá (p=0,022), el componente cariados del índice se vio significativamente aumentado. Se observó también, un índice aumentado de dientes obturados en los participantes con nivel máximo de posgrado (p=0,001). El grupo de fumadores mostró significancia estadística (p=0,034) en el índice de caries. Conclusiones. El índice CPOD poblacional se encontró en nivel bajo, estando el grupo de mayor edad significativamente por encima de los dos grupos de menor edad. Los niveles del componente cariados fueron más bajos en los habitantes de las regiones foráneas del estado y los que tenían escolaridad de posgrado (p=0,022 y p=0,02 respectivamente).Objective. To evaluate caries experience in university workers and to associate it with sociodemographic data. Methods. It was performed a descriptive cross-sectional, observational and analytic study in university workers from the University of Guadalajara, Mexico. Sociodemographic data was collected through a questionnaire and the DMFT index, through clinical evaluations. Statistical analysis of χ2, T-student, one-way ANOVA and Post-hoc were performed working with CI of 95%. Results. 290 participants agreed to oral examination, the average age of the interviewed workers was 36.2 ± 0.6. Women represented 55.9%. The DMFT of the evaluated sample was 8.3± 5.3. The χ2 analysis of the evaluated age ratio, showed statistical significance (p=0.0001). Similarly, the decay component of the index was increased in the one-way ANOVA test of the male group (p=0,0001) and of those who reside in Tonala (p=0.022). Additionally, an increased number of filled teeth was found in participants with postgraduate education (p=0.001). The smokers group showed statistical significance (p=0.034) in caries index. Conclusions. The broad DMFT index was found at a low level, however, the older age group was significantly different, being at the high level, well above the two younger age groups. The caries component of the DMFT index was significantly lower in the out of the region residents and those who had postgraduate degree (p=0.022 and p=0.02 respectively)

Cutinolytic Esterases are Induced by Growth of the Fungus Trichoderma harzianum on Glyceryl Monostearate in Solid-State Fermentation

Cutinolytic esterase are enzymes utilized in a wide variety of industrial applications, and they are capable of degrading emerging environmental pollutants. Due to the application and importance of these enzymes, it is crucial to develop an efficient method for cutinase production using a cost-effective inductor and an efficient microbial production system. In this work, the growth and cutinolytic esterase production of Trichoderma harzianum were evaluated in glucose-yeast extract media containing different glyceryl monostearate (GMS) concentrations (1, 3, and 5 g/L). It was used as inducer in solid-state fermentation. A medium lacking GMS was used as control. Biomass production and enzyme productivity were higher in inducer-added (1 g/L) medium than in the control medium. T. harzianum produced constitutive and inducible cutinolytic esterase, in which production was enhanced by GMS. In GMS-added cultures, two bands with cutinolytic esterase activity (60 and 150 kDa approximately) were observed by zymography, which were not observed in control culture. GMS represents a promising inducer for cutinolytic esterase production by fungi. This research represents the first approach for the study of cutinolytic esterase production using a synthetic molecule as an inducer

Effect of moisture content and inoculum on the growth and conidia production by Beauveria bassiana on wheat bran

The aim of the present work was to study the effect of moisture content and inoculum on the growth and conidia production by Beauveria bassiana on wheat bran (WB).The highest growth rate of B. bassiana 885.2 on WB media was obtained at a w=1.0, with no detected growth at a w < 0.97. Solid-state fermentation (SSF) using WB (66% moisture; a w=1.0) achieved a maximal yield of 1.18x10 10 conidia per gram of dry substrate (gds). This yield decreased one order of magnitude with higher moisture contents or the addition of sugarcane bagasse (SCB) as a texturiser. In SSF using WB (66% humidity),the time to obtain a yield of 1x10(10) conidia/gds, referred to as t10, could be predicted using a model considering common inoculum levels and maximal yields. For instance, t10 was 285 h with an inoculum of 1x10(6) conidia/gds; however, t10 was reduced to 232 h and 148 for inocula of 7x10(6) and 5x10(7) conidia/gds, respectively. The estimation of t10 values allowed both comparison between the cultures and prediction of harvesting times in production processes. Values for hydrophobicity were within 90 and 92%, whereas viability averages were around 70% for all the culture