Disinfection of water with new chitosan-modified hybrid clay composite adsorbent

Hybrid clay composites were prepared from Kaolinite clay and Carica papaya seeds via modification with chitosan, Alum, NaOH, and ZnCl2 in different ratios, using solvothermal and surface modification techniques. Several composite adsorbents were prepared, and the most efficient of them for the removal of gram negative enteric bacteria was the hybrid clay composite that was surface-modified with chitosan, Ch-nHYCA1:5 (Chitosan: nHYCA = 1:5). This composite adsorbent had a maximum adsorption removal value of 4.07 × 106 cfu/mL for V. cholerae after 120 min, 1.95 × 106 cfu/mL for E. coli after ∼180 min and 3.25 × 106 cfu/mL for S. typhi after 270 min. The Brouers-Sotolongo model was found to better predict the maximum adsorption capacity (qmax) of Ch-nHYCA1:5 composite adsorbent for the removal of E. coli with a qmax of 103.07 mg/g (7.93 × 107 cfu/mL) and V. cholerae with a qmax of 154.18 mg/g (1.19 × 108 cfu/mL) while the Sips model best described S. typhi adsorption by Ch-nHYCA1:5 composite with an estimated qmax of 83.65 mg/g (6.43 × 107 cfu/mL). These efficiencies do far exceed the alert/action levels of ca. 500 cfu/mL in drinking water for these bacteria. The simplicity of the composite preparation process and the availability of raw materials used for its preparation underscore the potential of this low-cost chitosan-modified composite adsorbent (Ch-nHYCA1:5) for water treatment

In vitro anticandidal and antioxidant potential of Mezoneuron benthamianum

Objective: To investigate the preliminary phytochemical screening and antioxidant properties of the methanolic extract of Mezoneuron benthamianum (M. benthamianum). Method: The anti-candidal potential and minimum inhibition concentration (MIC) were evaluated on fresh isolates of Candida species using disc diffusion method. While the lipophilic free radical scavenging activity was examined using the spectrophotometric assay on the reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH) and compared with standard antioxidant, α-tocopherol. Result: The anti-candidal activities of M. benthamianum root and leaf revealed zones of inhibition (ZI) against Candida glabrata as (13.6±1.00) mm and (13.7±1.00) mm respectively while, Candida krusei ZI against root (13.7±1.00) mm and leaf (11.8±0.80) mm as the most significant among other candida species (Candida stellatoidea, Candida albicans and Candida torulopsis). Phytochemicals present in the plant extracts includes saponin, anthracquinones, flavonoids and tannins. The antioxidant potential of the plant was significant and dose dependent at the concentrations tested. The extract has IC50 values of 781 μg/mL while the standard, α-tocopherol has 222.3 μg/mL. Conclusions: The result from this research suggests that M. benthamianum is a potent anti-candida and antioxidant plant and may be a potential anti-candida plant for future prospect in drug development

The Predominant Lactic Acid Microorganisms of Spontaneously Fermented Amala, a Yam Food Product

Aim: Using Four (4) varieties of yam (Dioscorea rotundata), namely, TDr Pepa, TDr Amila, TDr Alumaco and TDr 95/19177 differences in the types of organisms responsible for spontaneous fermentation were evaluated. The organoleptic properties of the final food products were also subjected to testing, in order to determine if these properties were reproducible. Study Design: Using a Complete Randomized Design (CRD) with three replications, the four varieties of yam were tested for significant differences in the characteristics of interest among the final products.  Place and Duration of Study: The present study was conducted between March and May 2016 at Ede. The yam tubers were sourced from the International Institute for Tropical Agriculture (IITA), Ibadan. Methodology: In a standardised spontaneous fermentation set-up, four varieties of yam, were sampled eight hourly over a period of 24 hours, for lactic acid microorganisms. Representative microbial populations that were incubated anaerobically were isolated, counted, identified and characterised using standard microbiological protocols. The final products were evaluated for their organoleptic properties. Results: The only isolated predominant lactic acid bacterial organisms was Lactobacillus brevis, while, Rhizopus spp, Aspergillus niger, Aspergillus flavus and Neurospora spp were identified as the representative lactic acid fungal isolates. The results revealed slight differences between the final products (amala samples) that were earlier processed using sun or oven-drying, although the differences were not statistically significant at p= .05 using  ANOVA (one-way analysis of variance). Conclusion: The present results confirmed that the prevailing microenvironment is the prime determinant of the predominant organisms in the fermentation process and consequently in the sensory properties of the final product. The present spontaneous fermentation data indicate that similar lactic acid organisms were isolated from the different yam varieties in the fermentation set up. The foregoing shows that the organoleptic characteristics specific to this test location may be reproduced using the isolated lactic acid microorganisms, perhaps on an industrial scale