RESUMO
The greatest limitation to utilization of maize stover by ruminants as a feed is the high concentration of lignin, which limits fibre digestibility. However, ruminants can effectively utilize maize stover if its nutritive value is improved using white rot fungal species. This study was designed to determine optimal bio-physical conditions for mycelial growth and select the most ideal fungal species and pre-treatment options for improving nutritive value of maize stover. Four popular edible Pleurotus fungal species (viz. Pleurotus florida, Pleurotus ostreatus, Pleurotus sajor caju and Pleurotus pulmonarius) were subjected to varying temperatures, pH levels, hydrogen peroxide (H2O2) concentration and illumination to establish the extent of mycelial growth rate. Inclusion of H2O2 was used to determine optimal levels for preservation and prevention of contamination from other indigenous microbiota. Effects of pre-treatment options on chemical composition and nutritive value of maize stover were also examined. Mycelial growth rate of Pleurotus species on potato dextrose agar (PDA) varied (P < 0.05) with temperature, pH level and H2O2 concentration following a quadratic trend. Optimal temperature, pH and H2O2 concentration for mycelial growth on PDA were 25 °C, 5 and 0.01 mL/L, respectively. Under the different bio-physical conditions, P. sajor caju had the highest mycelia density and growth rate. Chemical composition of solid-state fermented maize stover differed (P < 0.05) among the Pleurotus species. Maize stover fermented with P. sajor caju had the highest crude protein (CP) of 86.6 g/kg DM, in-vitro dry matter digestibility (IVDMD) of 731 g/kg DM, in-vitro organic matter digestibility (IVOMD) of 670.4 g/kg DM and metabolizable energy (ME) of 10.0 MJ/kg DM but with the lowest lignin (sa) of 50 g/kg DM. At 25 °C, P. sajor caju had the highest mycelial growth rate on PDA and highest lignin (sa) breakdown in the maize stover substrate. It was, therefore, selected as the most ideal fungal species for improving nutritive value of maize stover. Pre-treatment of maize stover with Lactobacillus plantarum and molasses under anaerobic condition for 7 days before inoculation with P. sajor caju resulted into a substrate with the highest (P < 0.05) CP (96.6 g/kg DM), IVDMD (752.3 g/kg DM), IVOMD (687.2 g/kg DM) and ME (10.2 MJ/kg DM). However, neutral detergent fiber exclusive of residual ash (NDFom) and lignin (sa) fractions decreased (P < 0.05) as a result of subjecting maize stover to pre-treatment with L. plantarum and molasses prior to fermentation with P. sajor caju. Therefore, pre-treatment of maize stover with L. plantarum and molasses for 7 days prior to fermentation with P. sajor caju for 14 days in darkness at 25 °C offered the greatest potential for breaking the lignin barrier.
RESUMO
INTRODUCTION: Certain oral manifestations signal progression of HIV disease among HAART naïve patients or an increase in the plasma HIV-1 RNA levels for those on treatment. Ranulas may be one of those manifestations. Therefore, this study describes the clinical features of patients who presented with ranulas including their demographics, HIV sero-status and the CD4 CD8 cell counts for those who were HIV positive. METHODS: A prospective study on ranulas was undertaken at Mulago national referral hospital and St Mary's hospital Lacor covering the period December 2008 to November 2009. RESULTS: Fifty-seven cases participated in the study: 38.6% male and 61.4% female. Out of the study group, 73.7% were HIV positive. This was statistically significant (Chi = 12.789, df = 1, p = 0.001). In relation, to CD4 cell count, 23.8% had <200 cells/mm(3), 35.7% between 200-500 cells/mm(3) and 40.5% more than 500 cells/mm(3). The CD4-to-CD8 ratio ranged from 0.02-0.98 with an average of 0.31 ± 0.23, median and mode of 0.27 and 0.32, respectively. CONCLUSIONS: It is felt that ranulas may be one of the oral manifestations of worsening immunity in HIV/AIDS disease. Therefore, more research is needed to establish if it should be included among known oral manifestations of the disease.