Lignocellulosic biomass, found in wooden plant husks is a potent renewable material source which can be utilised to form various chemicals and biomaterials including polyols such as xylitol. Xylitol has been used commercially as an alternative to sucrose in many products as bulk sweetener in non-cariogenic confectionery as well as in diabetic diets and solutions for parenteral nutrition. Therefore, this study aims to optimise separation parameters of the Shimadzu high performance liquid chromatography (HPLC) (Model No: LC-20A) and quantify the potential of coconut husk as substrate for Candida albicans in producing xylitol using HPLC. Pretreatment to depolymerise components of biomass i.e. cellulose, hemicellulose and lignin were done using dilute acid hydrolysis method which yielded fermentable reducing sugars, xylose. Xylose is a monosaccharide with an aldehyde functional group, a reducing sugar which is then utilised and fermented by the yeast Candida albicans to form xylitol. In this study, the media used for fermenting pretreated coconut husk and Candida albicans is a synthetic defined (SD) minimal broth. Growth curves against concentration of reducing sugar were plotted to determine utilisation and production trends with specific mixes of carbon sources. The presence of reducing sugars were tested using 3,5-dinitrosalicylic acid (DNS) assay in pretreated coconut husk yielded 13.22 g/L. In order to analyse the product with HPLC, an existing protocol is modified for Hypersil GOLD™ C18 column with acetonitrile as the mobile phase. Results obtained from HPLC analyses using developed protocol suggested the formation of xylitol from the fermentation of pretreated husk by Candida albicans. These can be followed by purification of fermented media in obtaining a better separation of contaminating peaks.
Lignocellulose is the most abundant renewable resource naturally available with great potential for bioconversion to value-added bio-products in this case from coconut husk to reducing sugar. This study was to isolate the lignocellulose bioconversion bacteria from cow dung and termite gut for reducing sugar production. CMC and Congo red dye was used as a selective media to screen for cellulose degrading bacteria while alkaline lignin media used to screen for lignin degrading bacteria. Coconut husk was pretreated using alkaline precipitation method. The 16s rRNA sequence analysis, Gram staining, motility test, crystal formation test and penicillin sensitivity test were used to confirm the bacteria identity. The reducing sugars production was monitor using 3, 5-dinitrosalicyclic acid (DNS) method. Bacterial enzymatic hydrolysis were facilitated through fermentation of 5 locally isolated bacteria at 6 shaking regimes which were 0rpm, 50rpm, 100rpm, 150rpm, 200rpm and 250rpm and conditions were fixed at pH7.0 and temperature 25oC. The total of 39 and 28 colonies were isolated from cow dung and termite gut respectively. The isolates T10, T19, T22, T24, C19, and C37 were identified as Bacillus thuringiensis, Enterobacter aerogenes, Bacillus pumilus, Bacillus vireti, Bacillus anthracis, and Bacillus thuringiensis. In PC medium, 2 bacteria strains, T19 and C37 showed the highest concentration of reducing sugar production (after 18 to 20 hours) which was 1.28 g/L at 150rpm (T19) and 1.27 g/L at 200rpm (C37). While in CMC medium, T19 and C37 also showed the highest concentration of reducing sugar production which was 0.72 g/L at 150rpm (T19) and 0.70 g/L at 200rpm (C37). These bacteria demonstrated significant (p < 0.05) to degrade cellulose was shown by measuring the diameter of clearing zone signifying metabolism of cellulose and also the ability to convert both PC and CMC to reducing sugars measurable by DNS method. This study suggests that the PC resulted in higher reducing sugar production compare to CMC at 150rpm and 200rpm by E. aerogenes and B. thuringiensis which these bacteria isolated from cow dung and termite gut. Future studies on metabolic pathway and specific reducing sugar produced may be done using High Performance Liquid Chromatography (HPLC) analysis.
Dermatophytosis is a widespread disease produced by pathogenic fungus particularly Trichophyton rubrum. The present study reports on the formulation and evaluation of topical gel containing Allium sativum, Curcuma longa, Andrographis paniculata and Alpinia galanga extracts for significant antifungal potential. Minimum Inhibitory Concentration (MIC) of single plant and combination including synergistic effects were also determined. Macrodilution method was used to determine the MIC against Trichophyton rubrum. Gel formulations were evaluated using physicochemical parameters such as color, appearance, pH, viscosity, spreadability and stability testing. Overall MIC values of extracts against Trichophyton rubrum ranged from 31.25 mg/mL to 500 mg/mL. The MIC for A. sativum, C. longa, A. paniculata and A. galanga respectively were 500mg/ml, 31.25mg/ml, 250mg/ml and 500mg/mL. However, the assessment of combinations of selected extracts showed indifferent and antagonism interactions. This study also revealed that the formulation containing C. longa showed better stability than other formulations. A. galanga gel formulation has good viscosity and spreadability making it a good candidate in the gel formulation with good efficacy as an antifungal. Thus, this herbal gel formulation showed potential used to inhibit growth of T. rubrum that can be the alternative treatment of dermatophytosis.