ABSTRACT
Aims@#To evaluate the antibacterial efficacy of ethyl acetate extract of Aspergillus flavus IBRL-C8 against Gram-positive and Gram-negative bacteria.@*Methodology and results@#In this experiment, an endophytic fungus which identified as A. flavus IBRL-C8 was extracted using ethyl acetate and methanol, from Senna siamea, prior to in vitro antibacterial test on eight Gram-bacteria. The results were significantly more enunciated to the ethyl acetate extract since the Gram-bacteria signified 9.0 to 20.0 mm of inhibition zones on Muller Hinton Agar (MHA) during disc diffusion assay. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of the extract were ranged from 125-1000 µg/mL and 125-2000 µg/mL, respectively. Time-kill assay depicted the ethyl acetate extract of A. flavus IBRL-C8 exceptionally retarded methicillin-resistant Staphylococcus aureus (MRSA) and also manifested extended antibacterial activity. The maximum reduction in cell numbers occurred at 2MIC concentration (250 µg/mL) during the interval time of 16 h. The malformations noticed from microscopic observations where the transformation of structural annihilation from regular spherical morphology to non-spherical shape with an irregular surface and also disruption around the cell membrane when the MRSA treated with ethyl acetate extract of A. flavus IBRL-C8. @*Conclusion, significance and impact of study@#This study proposed the ethyl acetate extract of A. flavus IBRL-C8 as a potential antibacterial agent against MRSA infection, which can be useful in pharmaceutical application.
Subject(s)
Aspergillus flavus , Anti-Bacterial AgentsABSTRACT
Aims@#This research was conducted to develop and characterize polyvinyl alcohol (PVA)/montmorillonite (MONT) clay incorporated with carvacrol (Carva) nanocomposite film as a potential material in wound dressing.@*Methodology and results@#Organophilic MONT clay, which was initially modified from commercial MONT clay by cetyltrimethylammonium bromide (CTAB), was used in the polymerization process using PVA. The synthesized nanocomposites were visualized via transmission electron microscopy (TEM). The developed film (PVA/MONT/Carva nanocomposite film) was characterized via Fourier transform infrared (FTIR). The investigation on mechanical property and antimicrobial activity of the film was also performed. All nanocomposites are spherical, with a size of 92.8 ± 22.1 nm. The -OH stretch, C-H stretch, aromatic group, SiO stretch, and C-O from acetyl group were identified in the PVA/MONT/Carva nanocomposite films. During the chemical release test, carvacrol attained a plateau at 24 h, with a total release of 62.3%. This nanocomposite exhibited a severe detrimental influence on the growth of Gram-bacteria and yeasts, which represented a broad spectrum of antimicrobial agents. All test microorganisms showed approximately up to 82% reduction of microbial growth during the Hohenstein challenge test. Physically, the nanocomposite films were yellowish and apparent. The film was sturdy, flexible, elastic and consisted of excellent water holding capacity.@*Conclusion, significance and impact of study@#PVA/MONT/Carva nanocomposite film may have a useful potential to be merged in the pharmaceutical application, especially in wound dressing production.
Subject(s)
Polyvinyl Alcohol , Bentonite , Wound HealingABSTRACT
Aims@#Endophytic fungi are organisms that colonize living plant tissues without causing significant symptoms of diseases. They are known as the repository of bioactive compounds. This study was aimed to isolate endophytic fungi associated with Aloe vera and to assess their antimicrobial activity against the diabetic wound pathogens that result to lower limb amputations. @*Methodology and results@#In this study, 84 endophytic fungi were isolated from A. vera by using 5% sodium hypochlorite and 70% ethanol as surface sterilants. On preliminary antimicrobial screening by agar plug assay, 12 (14.3%) isolates showed significant antagonistic activity on the test microorganisms. Two of the endophytes were identified as Aspergillus flavus and Colletotrichum gloeosporioides through morphological and molecular techniques. The fungal cultures fermented in shake flask were extracted subsequently with hexane, dichloromethane, ethyl acetate, and n-butanol. Ethyl acetate and dichloromethane extracts of A. flavus and C. gloeosporioides inhibited all test bacteria. The compounds in the extracts were seemed to be semi-polar in nature. On broth microdilution assay, minimal inhibitory and minimal lethality concentration of ethyl acetate extracts of the fungi were found in the range of 0.63−2.50 and 1.25−5.00 mg/mL, respectively. @*Conclusion, significance and impact of study@#This study reveals that A. vera harbours a wide diversity of endophytic fungi. A. flavus and C. gloeosporioides showing broad spectrum antimicrobial activity on wound pathogens may be potential sources of bioactive compounds. Further investigations should be conducted to isolate and identify the antimicrobial compound produced by these fungal isolates.
Subject(s)
AloeABSTRACT
@#Aims: Researchers found a wide range of therapeutic properties in Spirulina sp. including as anti-cholesterol or anti-hyperlipidemic agent. In this study, the lipid levels of domestic F. catuswere induced in order to scrutinize the anti-hyperlipidemic effects of local S. platensisLUQS1 strain, specifically at concentrations of 0.5g/day and 1.0 g/day.Methodology and results:Elevation of serum lipid levels viz. total cholesterol (TC), high density lipoprotein (HDL), low density lipoprotein (LDL) and triglycerides (TG) as well as the status of kidney [creatinine (Cr) and blood ureanitrogen (BUN)] were observed in four groups of F. catusfor 45 days. The highest levels for TC, LDL and TG (P<0.05) were recorded in high cholesterol diet group (CD) at day 45 with 291.67±2.87 mg·dL-1, 111.60±9.73 mg·dL-1and 146.33±10.44 mg·dL-1, respectively. HDL levels in Spirulina-treated groups (CA and CAA) were better than normolipidemic group (control, SD group), of which the maximum levels were displayed at day 30 specifically 72.87±6.08 mg·dL-1by cats-fed with high cholesterol diet treated with 0.5 g/day S. platensis LUQS1 (CA group). There were insignificant differences (P>0.05) in the BUN levels; however, the Cr levels in CAA group (day 30 and 45) were slightly out of normal range but did not classify under chronic condition. Conclusion, significance and impact of the study: Alternative treatments on hyperlipidemic cats were rarely reported by researchers and medicinal practitioners. Thus, the findings of this present study provided a genuine knowledge concerning the lipid-lowering effect of S.platensisLUQS1 on the hyperlipidem
ABSTRACT
Aims: A local fungal isolate, Aspergillus niger USM F4 produced high level of mannanase activity when cultivated in a shallow tray system (45 x 40 x 7 cm3) using palm kernel cake (PKC), an easily available cheap agricultural waste which are found abundantly in Malaysia. Methodology and Results: A range of 0.25 to 1.5 cm bed heights were investigated in tracking in the most suitable condition and maximum production of mannanase. The highest mannanase production of 918.68 U/g substrate was obtained on the fifth day of cultivation after using all the optimised cultural conditions that consisted of 400 g of PKC that equivalent to 0.50 cm of substrate thickness with the particle size of ≤ 0.5 mm, moisture content of 80% (w/w) with the addition of 2% (w/w) molasses as a carbon source and 4% (w/w) ammonium nitrate as a nitrogen source, inoculums size of 1x107 spores/ml, with once at every 24 h of mixing frequency and cultivation temperature at room temperature 30±2 °C. Conclusion, significance and impact of study: The results obtained from this study showed that a shallow tray system was suitable to be used for getting highest enzyme production in SSF. Besides using a bigger volume of substrate, the correct substrate bed height is also important.