Mycoflora and aflatoxin production in pigeon pea stored in jute sacks and iron bins

The mycoflora, moisture content and aflatoxin contamination of pigeon pea (Cajanus cajan (L.) Millisp) stored in jute sacks and iron bins were determined at monthly intervals for a year. The predominant fungi on freshly harvested seeds wereAlternaria spp.,Botryodiplodia theobromae, Fusarium spp. andPhoma spp. These fungi gradually disappeared from stored seeds with time and by 5–6 months, most were not isolated. The fungi that succeeded the initially dominant ones were mainly members of the generaAspergillus, Penicillium andRhizopus. Population of these fungi increased up to the end of one year storage. Higher incidence of mycoflora andAspergillus flavus were recorded in jute-sack samples throughout the storage period. The moisture content of stored seeds was found to fluctuate with the prevailing weather condition, being low during the dry season and slightly high during the wet season. The stored seeds were free of aflatoxins for 3 and 5 months in jute sacks and iron bins respectively. The level of aflatoxins detected in jute-sack storage system was considerably higher than that occurring in the iron bin system. Of 196 isolates ofA. flavus screened, 48% were toxigenic in liquid culture (54% from jute sacks and 41% from iron bins).     

Genome-scale metabolic reconstruction and <Emphasis Type="Italic">in silico</Emphasis> analysis of methylotrophic yeast <Emphasis Type="Italic">Pichia pastoris</Emphasis> for strain improvement

Background  

Pichia pastoris has been recognized as an effective host for recombinant protein production. A number of studies have been reported for improving this expression system. However, its physiology and cellular metabolism still remained largely uncharacterized. Thus, it is highly desirable to establish a systems biotechnological framework, in which a comprehensive in silico model of P. pastoris can be employed together with high throughput experimental data analysis, for better understanding of the methylotrophic yeast's metabolism.     

Effect of essential oils from two Nigerian medicinal plants (Azadirachta indica and Morinda lucida) on growth and aflatoxin B1 production in maize grain by a toxigenic Aspergillus flavus

The growth of a toxigenic Aspergillus flavus decreased progressively with increasing concentration of essential oils from leaves of Azadirachta indica , Morinda lucida and seeds of A. indica incorporated into SMKY liquid medium. The oils also significantly reduced aflatoxin synthesis in inoculated maize grains. Oils from A. indica seeds completely suppressed aflatoxin synthesis in inoculated maize at 500 and 1000 ppm while those of M. lucida also showed complete inhibition at 1000 ppm.     

Evaluation of damage of some food commodities by larger grain borer–Prostephanus truncatus (Horn) {Coleoptera: Bostrichidae} and microbial composition of frass induced by the insect

The microbial composition of the frass from maize (Zea mays) grains and seven dried root and tuber crops (R&TC) infested by Prostephanus truncatus were evaluated. Five cubes (6 cm³) of each R&TC as well as 100 g of maize grains were separately infested with 15 pairs of 1–2 day old adult LGB in 250 cm³ sized Kilner jars and incubated for 90 days at 28 ± 1°C and 79–82% RH. At 90 days post-infestation, the microbiological assay of frass from the commodities was performed. The results indicated the presence of 10 bacterial species, namely Bacillus cereus, B. macerans, Proteus mirabilis, P. morganic, P. rettgeri, Proteus sp., Pseud geniculatum, Pseud fragii, Pseud putela, Serratia marcences and six fungal species, namely Aspergillus niger, A. tamari, A. parasiticus, A. ochraceus, Fusarium compacticum and F. oxysporum. Infested cubes of M. esculenta have the highest population of adult LGB (168.3) and frass from its damaged cubes had the highest mean bacterial count of 30.0 × 10⁷ colony forming units (CFU) and it was significantly (P < 0.05) higher than LGB infestation and bacterial infection of other R&TC. The bacterial count from the damaged commodities correlated positively and significantly (P < 0.05) with weight of frass, percentage damage and percentage weight loss. The results revealed that frass from the LGB-infested and damaged commodities were infected by bacteria and fungi. Maize grains and dried R&TC should therefore be protected from LGB infestation to avoid quantity reduction and microbial infection.     

Apoptosis,cytokine and chemokine induction by non-structural 1 (NS1) proteins encoded by different influenza subtypes

Background

Influenza pandemic remains a serious threat to human health. Viruses of avian origin, H5N1, H7N7 and H9N2, have repeatedly crossed the species barrier to infect humans. Recently, a novel strain originated from swine has evolved to a pandemic. This study aims at improving our understanding on the pathogenic mechanism of influenza viruses, in particular the role of non-structural (NS1) protein in inducing pro-inflammatory and apoptotic responses.

Methods

Human lung epithelial cells (NCI-H292) was used as an in-vitro model to study cytokine/chemokine production and apoptosis induced by transfection of NS1 mRNA encoded by seven infleunza subtypes (seasonal and pandemic H1, H2, H3, H5, H7, and H9), respectively.

Results

The results showed that CXCL-10/IP10 was most prominently induced (> 1000 folds) and IL-6 was slightly induced (< 10 folds) by all subtypes. A subtype-dependent pattern was observed for CCL-2/MCP-1, CCL3/MIP-1α, CCL-5/RANTES and CXCL-9/MIG; where induction by H5N1 was much higher than all other subtypes examined. All subtypes induced a similar temporal profile of apoptosis following transfection. The level of apoptosis induced by H5N1 was remarkably higher than all others. The cytokine/chemokine and apoptosis inducing ability of the 2009 pandemic H1N1 was similar to previous seasonal strains.

Conclusions

In conclusion, the NS1 protein encoded by H5N1 carries a remarkably different property as compared to other avian and human subtypes, and is one of the keys to its high pathogenicity. NCI-H292 cells system proves to be a good in-vitro model to delineate the property of NS1 proteins.

     

STING Millennium Suite: integrated software for extensive analyses of 3d structures of proteins and their complexes

Background  

The integration of many aspects of protein/DNA structure analysis is an important requirement for software products in general area of structural bioinformatics. In fact, there are too few software packages on the internet which can be described as successful in this respect. We might say that what is still missing is publicly available, web based software for interactive analysis of the sequence/structure/function of proteins and their complexes with DNA and ligands. Some of existing software packages do have certain level of integration and do offer analysis of several structure related parameters, however not to the extent generally demanded by a user.     

Microbial oxidation of naphthalene to cis-1,2-naphthalene dihydrodiol using naphthalene dioxygenase in biphasic media

The selective oxidation of aryl substrates to chiral cis-1,2-dihydrodiols is an industrially important reaction for the production of intermediates that can be used to produce fine chemicals, pharmaceuticals, and many other bioactive natural products. More specifically, the oxidation of naphthalene to produce optically pure (+)-cis-(1R,2S)-1,2-napthalene dihydrodiol (NDHD) to be used as a chiral synthon for specialty chemicals has gained much interest. Escherichia coli JM109(DE3) pDTG141 expresses naphthalene dioxygenase which catalyzes this reaction. Poor substrate solubility and substrate toxicity are barriers to using the power of these enzymes in large-scale aqueous whole cell systems. A biphasic reaction system was chosen to overcome these barriers. The optimal biphasic conditions for E. coli JM109(DE3) pDTG141 were determined to be 20% dodecane as the organic solvent containing 40 g/L naphthalene. The productivity of the biotransformation using resting cells was 1.75 g-diol/g-cdw/h for the first 6 h with 20% organic phase, which was increased from 0.59 g-diol/g-cdw/h for growing cells with 40% organic phase. The biocatalytic activity was retained for at least 12 h. The biocatalyst could be recycled for at least four runs in both suspended and immobilized form. The stability of the 12 h recycle was improved by immobilization in calcium alginate beads. The process has been improved both environmentally and economically by reducing the amount of solvent used and by recycling the biocatalyst.     

Abortion-seeking behaviour among Nigerian women

This study used data from a community-based survey to examine women's experiences of abortion in Nigeria. Fourteen percent of respondents reported that they had ever tried to terminate a pregnancy, and 10% had obtained an abortion. The majority of women who sought an abortion did so early in the pregnancy. Forty-two percent of women who obtained an abortion used the services of a non-professional provider, a quarter experienced complications and 9% sought treatment for complications from their abortions. Roughly half of the women who obtained an abortion used a method other than D&C or MVA. The abortion prevalence and conditions under which women sought abortions varied by women's socio-demographic characteristics. Because abortion is illegal in Nigeria except to save the woman's life, many women take significant risks to terminate unwanted pregnancies. Reducing the incidence of unwanted pregnancy and unsafe abortion can significantly impact the reproductive health of women in Nigeria.     

A rapid plate culture method for screening of amylase producing micro-organisms

A simple and rapid method is described for the detection of amylase-producing micro-organisms on solid media using Remazol Brilliant Blue-starch as substrate. The blue starch is incorporated into nutrient agar and amylase production is detected by the disappearance of the colour around the colonies. The method which is non-destructive, allows for direct visualization and isolation of amylolytic micro-organisms from the environment without prior replication of colonies.     

In vitro effect of fermented maize slurry and ethanol extracts of five plants against Sclerotium rolfsii Sacc. of tomato (Lycopersicon esculentum Mill.)

Sclerotium rolfsii Sacc. is an important fungal pathogen affecting the production of tomato (Lycopersicon esculentum Mill.). Conventional control methods using chemicals are expensive, which constitute environmental hazards. This has necessitated the search for alternatives in botanicals. Ethanol and supernatant solution of fermented maize slurry extracts from Ocimum gratissimum, Cymbopogon citratus, Xylopia aethiopica, Aframomum melegueta and Allium sativum were evaluated. In vitro test was carried out at 1, 2, 3, 4 and 5% concentrations against the pathogen. Mycelial growth was significantly reduced in the following descending order: O. gratissimum?>?A. melegueta?>?A. sativum?>?X. aethiopica?>?C. citratus. Supernatant solution extracts of O. gratissimum and A. melegueta at 5% concentration gave highest mycelial reduction (0.00?mm), respectively, while O. gratissimum ethanol extract recorded highest mycelial reduction (0.23?mm) among the ethanol extracts. Supernatant solution of fermented maize slurry extracts of O. gratissimum and A. melegueta at 5% concentration was more effective in reducing mycelial growth of S. rolfsii.