Performance of Metarhizium rileyi Nm017: nutritional supplementation to improve production and quality conidia.

This study aimed to analyze the effect of nutritional supplements on improving conidia production of Metarhizium rileyi Nm017 at laboratory scale (yields of conidia/substrate and biomass/substrate, and substrate consumption). Also, the influence on quality parameters were evaluated (germination at 36 and 48 h, enzymatic activity, and insecticidal activity on Helicoverpa zea). Six treatments (T1-T6) were assessed and all of them reached maximum conidia concentration after 7 days fermentation, a feasible production timetable. Yields from treatment T6 (yeast extract + V8 juice) were 1.5-threefold higher than the other treatments. Conidia from T6 reached germinations of 56% and 12% at 36 and 48 h, respectively, higher than T1 (without supplements), which had the lowest values found. M. rileyi conidia obtained from treatment T6 had the highest enzymatic activity (0.45 U chitinase g-1, 0.28 U lipase g-1, and 1.29 U protease g-1). However, treatments with the highest conidia yields and enzymatic activity were not positively correlated to the efficacy against H. zea. When M. rileyi was produced on T5 (yeast hydrolysate + V8 juice), conidia were 35% more virulent than treatment T6. The findings evidenced the noticeable impact of nutritional substrate amended for conidia production and quality. This work showed the relevance of insecticidal activity assessment as a selection criterion in the mass production development of a biocontrol agent.

Nematode predatory ability of the fungus Duddingtonia flagrans affected by in vitro sequential exposure to ovine gastrointestinal tract.

Duddingtonia flagrans is a nematophagous fungus employed as a biocontrol agent of gastrointestinal nematodes in ruminants. After oral ingestion and passage through the digestive tract of animals, this microorganism captures the nematodes in the feces. The drastic conditions of ruminant digestive tract could affect fungi chlamydospores and therefore biocontrol activity. The aim of this study was to evaluate in vitro the effect of four ruminant digestive segments on the concentration and nematode predatory ability of a Colombian native strain of D. flagrans. The sequential four-step methodology proposed evaluated conditions of the oral cavity, rumen, abomasum, and small intestine such as pH (2, 6, 8), enzymes (pepsin, pancreatin), temperature (39 °C), and anaerobiosis comparing short (7 h) and long (51 h) exposure times. The results showed that the nematode predatory ability of the fungi is affected by sequential exposure to gastrointestinal segments and this effect depends on the exposure time to those conditions. After short exposure (7 h) through the four ruminant digestive segments, the fungi had a nematode predatory ability of 62%, in contrast, after long exposure (51 h) the nematode predatory ability was lost (0%). Moreover, the number of broken chlamydospores was higher in the long-exposure assay.

Assessment of a potential bioproduct for controlling Cerotoma arcuata tingomariana (coleoptera: Chrysomelidae).

AIMS: The leaf-feeding pest Cerotoma arcuata tingomariana (Bechyné) (Coleoptera: Chrysomelidae) produces huge economic losses in different crops. This study aimed to produce conidia by semisolid-state fermentation and to establish the insecticidal activity of two formulation prototypes based on a native Beauveria bassiana isolate for controlling this pest. METHODS AND RESULTS: A novel fabric-based semisolid-state fermentation strategy for quick and large-scale conidia production was performed and characterized. Conidia were formulated as an emulsifiable concentrate (EC) and a water-dispersible granulate (WG). Afterwards, the mortality of C. a. tingomariana adults was assessed. A conidia concentration of 2.9 × 109 conidia cm-2 was obtained after 9 days-course fermentation and a yield of 33.4 g kg-1 dry-substrate. CONCLUSIONS: The polyester fabric-based fermentation is an efficient technique for producing and collecting B. bassiana spores. Regarding LC90 , the potency analysis showed that the EC was 21-fold more potent than the non-formulated conidia, and ~ 2.6-fold more potent than the WG. SIGNIFICANCE AND IMPACT OF STUDY: A high throughput fermentation based on polyester fabric as support for B. bassiana conidia production and subsequent formulation as an EC comprises a promising strategy for obtaining a bioproduct to control adults of C. a. tingomariana and other Chrysomelidae pests.

Formulation Process Analysis of a Virus-based Biopesticide to Control the Tomato leafminer Tuta absoluta

Abstract: Virus-based biopesticides are effective biocontrol agents of crop insect pests. Development of suitable formulations and production processes are necessary to obtain high-quality products easily adopted by farmers. A detailed unit operation study was carried out for the production process of a Phthorimaea operculella granulovirus-based biopesticide to control the tomato leafminer, Tuta absoluta, one of the most important pests affecting this crop. Physicochemical, microbiological, and insecticidal parameters were implemented in the process and applied to the finished product, and a scaling strategy was developed. A Quantitative Polymerase Chain Reaction (Q-PCR) technique was implemented to quantify viral concentrations in the active ingredient (5.34 ± 1.44 x109 Occlusion Bodies mL-1) and in the finished product (>1.6x109 OB mL-1), without contaminant interferences. The Q-PCR methodology was also useful to select the appropriate solid mixing time following Lacey´s mixing index (8 min). Factors and similarity principles influencing the liquid mixing process were identified in the scaling evaluation. Furthermore, the drying kinetics analysis enabled identifying a drying temperature of 35 °C, with an efficacy under controlled conditions higher than 97%. Contaminant concentration was lower than 1%, indicating controlled and aseptic formulation process conditions. A simple statistical method was used to estimate the reproducibility and repeatability of the parameters assessed in the finished product. These results enable to establish and extrapolate important parameters in the standardization, scale-up, and quality control for the granulovirus-based biopesticide.

Scale-Up of Duddingtonia flagrans Chlamydospores Production from Laboratory to Pilot-Scale Using a Solid-State Fermentation System.

The fungus Duddingtonia flagrans is a biological control tool to reduce infective larvae of gastrointestinal nematode in pastures. To create a commercially available bioproduct based on a nematophagous fungus, an efficient mass production process should be developed that is able to guarantee a good predatory capacity and satisfactory production rates. In this work, solid-state fermentation (SSF) parameters were investigated to produce D. flagrans at pilot-scale. The results showed that the relative humidity was a critical factor to increase productivity and to reduce fermentation time. The best production conditions using a tray bioreactor were a relative humidity in the room at 90% for 2 days, and inoculation by sprinkling. The fermentation process was composed of 7 days under submerged fermentation to produce the inoculum and 7 more days of SSF in a tray bioreactor. The productivity reached was 4.96 × 106 chlamydospores g-1 of dry substrate day-1, which is the highest productivity reported to date. The predatory capacity of the chlamydospores produced using this process was 91%. Also, a statistical control process analysis was applied, finding that the process presents stability in the biological activity, yield, and final moisture content of the substrate between batches. Finally, the operational expenses (OPEX) based on the use of the heating and humidification system were estimated, given a final cost of 0.20 USD g-1 of the fermented substrate.

Clinical practice guideline. Integral Care Guidelines for the prevention, early detection and treatment of pregnancy, childbirth and puerperium complications: Section on toxoplasmosis in pregnancy / Guia de atencion integral para la prevencion, deteccion temprana y tratamiento de las complicaciones del embarazo: Sección de Toxoplasmosis

Como parte de la Guia de atencion integral para la prevencion, deteccion temprana y tratamiento de las complicaciones del embarazo, desarrollada y financiada por el Departamento de Ciencia, Tecnologia e Innovacion, Colciencias, y el Ministerio de Salud y Proteccion Social de Colombia, se seleccionó a la infeccion por Toxoplasma para el desarrollo de recomendaciones para su prevencion, diagnostico y tratamiento. La infeccion por Toxoplasma gondii (T. gondii) durante el embarazo puede resultar en graves complicaciones para el feto y dejar importantes secuelas al recien nacido. Se realizo una guia basada en la mejor evidencia disponible en la literatura cientifica, con especial pertinencia a la informacion colombiana. Un consenso de expertos en parasitologia, ginecologia, neonatologia e infectologia, tanto de adultos como pediatrica, desarrollo las recomendaciones. Se propone que las recomendaciones de esta guia de atencion integral sean utilizadas por los profesionales de salud de los programas de atencion del embarazo del pais con el fin de disminuir la morbilidad y mortalidad atribuible a esta enfermedad. Se formulan recomendaciones especificas para el diagnostico desde el primer trimestre, consejos de prevencion en las mujeres no infectadas, identificacion de la infeccion del feto o del recien nacido y recomendaciones de tratamiento en estos escenarios.

Toxoplasma infection, an aspect included in the Integral Care Guidelines for prevention, early detection and treatment of complications during pregnancy developed and sponsored by the Department of Science, Technology and Innovation, Colciencias and the Ministry of Health and Social Protection; was selected to develop recommendations that may contribute to its prevention diagnostic and treatment. Guidelines were developed through systematic review of literature, two panels of evaluation, gradation of evidence: SIGN (Scottish Intercollegiate Guidelines Network), discussion panel with users and patients, external evaluation and socioeconomical evaluation of the impact of recommendations. The Toxoplasma gondii infection that occurs during pregnancy may cause serious complications for the fetus and important sequelae for the newborn. A clinical guideline based on the best available scientific evidence, with emphasis on Colombian references, was performed. Experts in parasitology, neonatology and infectious diseases (adult and pediatric) developed the recommendations. It is suggested that the recommendations included in this guideline be followed by healthcare professionals in pregnancy care programs nationwide, with the purpose of lowering the morbidity and mortality related to this disease. Specific recommendations for diagnosis during the first trimester of the pregnancy, recommendations for prevention in noninfected women, identification of fetal or newborn infection and recommendations for treatment in those given cases are included.

Microencapsulation of a Colombian Spodoptera frugiperda Nucleopolyhedrovirus with Eudragit® S100 by spray drying

A Colombian Spodoptera frugiperda nucleopolyhedrovirus NPV003 with high potential for the development of an efficient biopesticide was microencapsulated by spray drying with a pH dependent polymer (Eudragit® S100). Conditions for microparticles production were standardized and microencapsulation process was validated. Physical properties, insecticide activity and photo-stability of microencapsulated virus were determined. The microparticles were spherical and irregular shaped, with sizes between 17.64 and 19.47 µm. Moisture content was 10.38 ± 0.87%; encapsulation efficiency 84.61± 13.09% and process yield was 91.20 ± 6.40%. Microencapsulation process did not affect viral insecticidal activity and provided efficient protection against UVB radiation. Results demonstrated technological feasibility of spray drying process to be used in formulating a biopesticide based on NPV003.