Tratamiento biológico de madera para eliminar pitch en la producción de celulosa

Se realizó un estudio biotecnológico para abatir el contenido resinoso de astilla de pino del estado de Durango y evitar los problemas asociados con la formación de pitch en la producción de pulpa mecánica. Se aislaron 49 cepas nativas que degradaron ácidos resínicos y precursores de pitch. Entre las mejores cepas se identificaron a Paecilomyces sp., Penicillum sp., Phialophora sp., Trichosporon sp., Rhodotorula sp., Cryptococcus sp. y Chryseomonas luteola. Esta última fue la más eficiente con un rendimiento de 87,3 % a nivel matraz, por lo que fue probada preliminarmente en fermentación sólida tipo heap leaching. La cepa Paecilomyces sp. rindió 86,6 % de efectividad a nivel matraz y fue probada en fermentación semisólida. Los resultados de las pruebas a nivel matraz fueron muy superiores a los obtenidos de manera preliminar en las fermentaciones sólidas.

Chryseomonas luteola from Bile Culture in an Adult Male with Severe Jaundice

ABSTRACTA 60-year-old male was admitted in this hospital with severe jaundice, who had open cholecystectomy done 2 months ago. ERCP was performed and bile was sent for culture. It grew Chryseomonas luteola in pure culture. He underwent hepaticojejunostomy after 1 month. Total bilirubin improved gradually. His condition was stable on discharge. Prompt diagnosis of non-fermenters is required, as some of them are resistant to multiple antibiotics. Clinicians have to be made aware of the pathogenic role of C. luteola and its resistance to ampicillin and cephalosporins.

Efficacy of rhizobacteria for growth promotion in sorghum under greenhouse conditions and selected modes of action studies

SUMMARYThe screening of rhizobacteria for growth promotion of sorghum (Sorghum bicolour(L.) Moench) was conducted under greenhouse conditions for a total of 78 bacteria isolated from the rhizosphere of sorghum in Ethiopia, and 86 isolates from the rhizosphere and rhizoplane of grasses in South Africa. Three isolates from Ethiopia, all identified asBacillus cereus, enhanced growth promotion by resulting in statistically significant increases in at least five parameters. Of these,B. cereus(KBE7-8) resulted in significant increase in shoot and root biomass. Among effective isolates from South Africa,B. cereus(NAS4-3) andStenotrophomonas maltophilia(KBS9-B) showed significant increases in all the parameters measured. The isolates which resulted in significant growth promotion colonized the roots effectively with a count up to ⩾108cfu/g. In the study conducted to elucidate the possible modes of action by these effective isolates, indole 3-acetic acid-like substances were detected in culture filtrates of the isolates ranging from 4·2 μg/ml bySerratia marcescens(KBS9-R) to 22·8 μg/ml byB. cereus(KBS5-H) in the presence of 2 mg tryptophan/g nutrient broth solution. Higher rates of solubilization of tricalcium phosphate on Pikovskaya agar medium were shown byChryseomonas luteola(KBS5-F),S. marcescens(KBS6-H) andB. cereus(KBE9-1). There is very limited knowledge of the use of rhizobacteria in agriculture in Ethiopia and South Africa. The current study therefore generates valuable information towards application of plant growth promoting rhizobacteria as alternatives to chemical fertilizers.