Calcium regulation of carbohydrate modification in sorghum

Two improved Nigeria sorghum cultivars (KSV 8 and ICSV 400) were used to evaluate the effects of steep water Ca2+ treatment on carbohydrate modification in sorghum. The response of all the carbohydrate mobilization indicators evaluated [- and - amylases, diastatic activity (DP), extract andcold water soluble carbohydrates (CWS-carbohydrates)], to steep water Ca2+ treatment was highly significantly (p 0.001) cultivar and steep water Ca2+ treatment dependent. In contrast to KSV 8, Ca2+ treatment generally caused significant repression of -amylase development in ICSV 400. Development of -amylolytic activity in KSV 8 was however, significantly repressed by Ca2+ treatment. Interestingly, - amylase activity constituting well over 80% of total diastatic activity was attained in ICSV 400 grainssubjected to 100 ppm Ca2+ treatment. Hot water extract (HWE) showed statistically insignificant (p 0.1) linear variation with Ca2+ treatment. Although Ca2+ treatment significantly (p .001) repressed  CWS carbohydrates in both cultivars, significantly higher CWS-carbohydrates and HWE were released in ICSV 400 for each DP unit than the corresponding DP in KSV 8 malts would permit. Thus, suggesting important roles for factors other than DP, possibly proteolysis, in determining HWE and  CWS carbohydrates. The benefits of reduced kernel growth and malting loss were neutralized by the general repression of carbohydrate modification indices for both cultivars

The effects of calcium regulation of endosperm reserve protein mobilization of the Nigeria sorghum cultivars, ICSV 400 and KSV 8 during malting

The effects of steep liquor calcium ion on sorghum endosperm reserve protein mobilization were evaluated using two improved Nigeria sorghum cultivars (ICSV 400 and KSV 8). The key protein modification factors evaluated were free amino nitrogen (FAN), total non protein nitrogen (TNPN) and soluble protein of cold water extract (CWS-P). Ca2+ treatment highly significantly (P < 0.001) repressed FAN development in both sorghum cultivars ICSV 400 and KSV 8. TNPN accumulation significantly enhanced in ICSV 400 by Ca2+ treatment in contrast to KSV8 malts which showed 23 to 69% repression. Similarly, Ca2+ treatment was effective in stimulating peptide accumulation in ICSV 400 at all levels of treatment indicating that the enhancement of TNPN accumulation in this cultivar was derived mainly from the stimulation of peptide accumulation. KSV 8 in contrast showed highly significant repression of peptide accumulation. Protein solubilisation, soluble protein accumulation and cold water soluble protein modification in both cultivars were all highly significantly repressed by Ca2+ treatment; although, ICSV 400 appeared to be better modified. Carboxypeptidase development was stimulated significantly by Ca2+ treatment in both cultivars. Existence of multiple high points in  carboxypeptidase activity suggests heterogeneity of this enzyme in sorghum while Ca2+ treatment caused reduced proteinase development in ICSV 400, the enzyme activity was enhance in KSV 8 albeit marginally.Key words: Sorghum malt, steep water Ca2+ treatment, modification, free amino nitrogen, total non protein nitrogen, carboxypeptidase

Effect of Different Steeping Conditions on the Peroxidase Activities of Some Improved Sorghum Varieties

In order to evaluate the impact of duration and the incorporation or  otherwise of air rest during steeping on the peroxidase activities of  sorghum grains, five improved varieties were studied. Steeping durations used ranged from 0 (raw grains) to 72 hours, in two formats: with air rest and without air rest. Results obtained showed that among the raw grains which were the control experiment, variety SK5912 gave the highest  peroxidase activity, followed by variety KSV 8 while variety CSRO2 had the least peroxidase activity. During steeping, we observed that in almost all cases, higher peroxidase activities were obtained with air rested sorghum grains than those without air rest. In terms of how the different varieties compared during steeping, we found that variety KSV 8 gave the highest peroxidase activity at both with and without air rest regimes in all the steeping periods used. Also, we observed that in all cases, the highest increase in peroxidase expression was obtained during the first 6 hours of steeping, shown by a steep rise of over 50% increase in activity. The other steeping times following the first 6 hours however showed just gradual  increases in peroxidase over the period of sorghum. The major significance of this result is that although increasing duration showed increased  peroxidase activities, such increases were less jumpy than those obtained during the first 6 hours. Therefore, long steeping times may not  necessarily be very beneficial, with the added benefit that costs associated with long steeping durations may be avoided.Key words: Sorghum, cereals, peroxidases, enzymes, steeping, germination, air rest

Conference summary report of the 10th Annual General and Scientific Meeting of the Nigerian Society of Neonatal medicine (NISONM) held in Ibadan, Nigeria on 4th -7th July, 2017

The 10th Annual General and Scientific Meeting (AGSM) of the Nigerian Society of Neonatal Medicine (NISONM) took place in Ibadan, South -West Nigeria. The theme of the conference was: Imperatives in neonatal survival initiatives in Nigeria: The current state. The conference addressed a variety of topics relevant to newborn health from eminent speakers from across the globe. The four-day conference included preconference workshops and community mobilization/ health outreach in Lagelu local government area

Antimicrobial activities of lactic acid bacteria isolated from akamu and kunun-zaki (cereal based non-alcoholic beverages) in Nigeria

Three lactic acid bacteria (LAB) isolates designated AS1, AS2 and KN4 isolated from kunun-zaki (a sorghum based non-alcoholic beverage widely consumed in Northern Nigeria) and identified as Lactobacillus plantarum, Lactobacillus brevis and Lactobacillus delbruckii, respectively, produced significant inhibitory compounds in broth. The partially purified inhibitory compounds were screened by agar spot assay method for antagonistic activity against target Gram positive and negative bacteria as well as yeasts associated with food spoilage. The partially purified compounds exhibited strong activity against Staphylococcus aureus ATCC 12600, Bacillus cereus and Escherichia coli ATCC 11775. The inhibitory compound produced by AS1 and KN4 inhibited Bacillus subtilis. Only the inhibitory compound produced by AS1 affected Candida albicans and Candida krusei. Analysis of variance indicated that there was a significant difference (P<0.05) in the susceptibility of the different target organisms to partially purified inhibitory compounds. Gram positive bacteria were affected more than yeasts. Proteolytic enzymes, trypsin and pepsin, but not catalase and α-amylase, completely inactivated antagonistic activity of the compounds demonstrating their proteinacious nature. The inhibitory compounds were fairly heat stable and also stable over broad pH ranges. The use of these or related GRAS isolates in the production of this and related beverage may increase the safety, shelf life and marketing appeal of such beveragesKeywords: Bacteriocins, lactic acid bacteria (LAB), target organisms, antimicrobial activity.African Journal of Biotechnology, Vol 13(29) 2977-298

Effects of Different Carbon Sources on Biosurfactant Production by a Pseudomonas fluorescens Isolate

The production and surface active properties of biosurfactants synthesized by a strain of Pseudomonas fluorescens using different carbon sources were investigated. Biosurfactant synthesis was determined by measuring surface tension and emulsifying index of the product. The microorganism was able to grow and produce biosurfactants on the various carbon sources. Maximum production of biosurfactants, based on CMC-1, was obtained with soybean oil as carbon source. The minimum surface tension value of 40.3 dynes/cm was obtained with glucose as carbon source while soybean oil gave the highest surface tension value of 48.2 dynes/cm. The biosurfactants produced by the microorganism were able to form stable emulsions with various oils. The emulsification index ranged between 55% and 76%. The Pseudomonas fluorescens isolate used in the present study is a good microorganism for production of biosurfactants that have useful properties for many industrial applications.Keywords: Biosurfactant, Carbon sources, Microbial isolate, Pseudomonas fluorescen

Screening of malting sorghum samples for lactic acid bacteria with potentials for antimicrobial activity

Three varieties of sorghum grains (SK 5912, KSV 400 and KSV 8) undergoing malting process were screened for lactic acid bacteria (LAB) with antimicrobial activity and characterized using standardmethods. Out of fifty-seven lactic acid bacteria isolates, eighteen isolates with antimicrobial producing potential were selected for further study. The isolates displayed significant (p < 0.05) inhibitory activityagainst two indicator strains Escherichia coli ATCC 111755 and Staphylococcus aureus ATCC 12600. Eleven of these inhibitor-producing isolates secreted inhibitory compounds that were sensitive tocatalase while compounds from the other seven isolates continued to display inhibitory effect against the indicator strains after treatment with catalase. The proteinaceous nature and inactivation bycatalase of these inhibitory compounds from the seven bacteria identified them as bacteriocins. Based on standard biochemical and microbiological tests, the isolates were tentatively identified as belonging to Lactococcus spp., Leuconostoc spp., Lactobacillus spp. and Streptococcus spp. However, three isolates (GS3A, S6A and S10B) were tentatively identified as Lactobacillus reuteri, Lactobacillusfermentum and Lactobacillus acidophilus, respectively. LAB isolated from three varieties of sorghum grains undergoing malting exhibited the ability to produce bacteriocin and hydrogen peroxide

Selection and characterisation of high ethanol tolerant Saccharomyces yeasts from orchard soil

Six yeast strains with different levels of ethanol tolerance were isolated from orchard soil. Out of the six isolates, isolate Orc 6 showed the highest ethanol tolerance (20%) while isolates Orc 2 and Orc 11 had15% ethanol tolerance. High level ethanol tolerant Saccharomyces yeast, Orc 6, was investigated for its potential application in ethanologenic fermentations. Data presented in this study revealed that Orc 6 yeast isolate tolerated osmotic stress above 12% (w/v) sorbitol and 15% (w/v) sucrose equivalent of osmotic pressure thus exhibiting superior osmotolerance than the reference production wine yeast strain. Invertase activity was also higher for Orc 6 yeast when grown in both sorbitol and sucrose media. Sorbitol increased yeast sedimentation rate in contrast to sucrose. Generally, the new yeast strain, Orc 6, showed superior fermentative performance compared to the reference production yeaststrain

On the pH and Osmotic Stress Tolerance of High Ethanol Tolerant Palm Wine Saccharomyces Yeast Isolates

Saccharomyces yeast strains Y13, Y522 and Y1189 isolated from fermenting palm wine juice showed marked differences in their optimum growth pH and possessed osmotolerance comparable to established industrial yeast strains. Shifts in medium pH beyond the growth optimum elicited obvious reductions in growth rate as depicted by the decrease in mean log growth rate (K) and influenced the response of the test yeasts to osmotic stress. Key Words: Osmotolerance, Ethanol tolerance, Osmotic stress, Saccharomyces Bio-Research Vol.2(1) 2004: 1-