1. An antifungal peptide from the coconut
H X Wang, T B Ng Peptides. 2005 Dec;26(12):2392-6. doi: 10.1016/j.peptides.2005.05.009.
A chromatographic procedure consisting of ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on CM-cellulose, and gel filtration by fast performance liquid chromatography on Supedex 75 was utilized to isolate a 10 kDa antifungal peptide from coconut flesh. The peptide was unadsorbed on DEAE-cellulose, but adsorbed on Affi-gel blue gel and CM-cellulose. It displayed antifungal activity against Fusarium oxysporum, Mycosphaerella arachidicola and Physalospora piricola. The IC50 values of its inhibitory activities on mycelial growth in M. arachidicola and HIV-1 reverse transcriptase activity were respectively 1.2 and 52.5 microM.
2. Coconut Bio-yoghurt Phytochemical-chemical and Antimicrobial-microbial Activities
Heba Hassan Salama, Samy Mohamed Abdelhamid, Raouf Mohamed Kamel El Dairouty Pak J Biol Sci. 2019 Jan;22(11):527-536. doi: 10.3923/pjbs.2019.527.536.
Background and objective: Coconut flour is known to be highly nutritious flour and contains high dietary fiber. The aim of this study was to make "bio-yoghurt beverage grafted with coconut flour and containing probiotic bacteria which is recommended as a functional milk product. Materials and methods: Chemical, phytochemical studies and antimicrobial activity have been performed on coconut flour which was used to make the beverage. Bio-yoghurt beverages made with different ratios of coconut flour (0, 2, 4 and 6%) were chemical, microbiological and sensory tested when fresh and during storage for 15 days of cold storage. Results: Chemical composition of coconut flour showed reasonable contents of moisture, ash, fat, fatty acids, protein, crude fiber, total solids, total phenols and antioxidants. Coconut flour showed antibacterial activity against some foodborne pathogenic bacteria. The addition of coconut flour to make bio-yoghurt beverages increased its contents of total solids, protein, ash, fiber, acidity, antioxidant activity, total phenols, improved yoghurt sensory and rheological properties especially when probiotic bacteria were used. The results did not reveal any significant differences (p>0.05), between the bacterial counts of yoghurt starter culture, Lactobacillus rhamnosus, Lactobacillus casei in yoghurt control (without coconut) and bio-yoghurt treatments (with coconut), during cold storage. Moulds and yeasts were not detected in all bio-yoghurt treatments; meanwhile they appeared in yoghurt control after 15 days indicating coconut antifungal activity and subsequently a period of time to save more for this drink. All bio-yoghurt beverages with different ratios of coconut flour were sensory accepted and showed more favorable properties, particularly for the viscosity. Conclusion: A new functional dairy product of bio-yoghurt beverage contain coconut flour high fiber content was prepared with probiotic bacteria and showed good chemical, microbiological and sensory/rheological properties.
3. Isolation of an antifungal Paenibacillus strain HT16 from locusts and purification of its medium-dependent antagonistic component
W-W Zhou, J-X Huang, T-G Niu J Appl Microbiol. 2008 Sep;105(3):912-9. doi: 10.1111/j.1365-2672.2008.03822.x. Epub 2008 Apr 16.
Aims: To isolate an antagonist for use in the biological control of the phytopathogenic fungus Penicillium expansum and purify the antifungal component produced by the antagonist. Methods and results: An antifungal strain HT16 was isolated from locusts, showing strong inhibition to Pen. expansum. Based on its in vitro effectiveness, HT16 was characterized as a strain of Paenibacillus polymyxa by phenotypic tests and 16S rDNA sequence analysis. It was found that the antifungal component HT16 secreted was only induced by Poria cocos sclerotium (PCS), and it remained active after sterilization at 121 degrees C for 15 min. The protein was purified by ammonium sulfate precipitation, heating process, and ultrafiltration using a 10 kDa cut-off membrane. The molecular weight of the purified antifungal protein, which was determined by mass spectrometry, was 4517 Da. Conclusions: A novel bacterial strain HT16 antagonistic to Pen. expansum was isolated from locusts and identified as Pae. polymyxa. The antifungal protein of 4517 Da was purified, and its production needed the inducer PCS in the fermentation medium. Significance and impact of the study: The antagonistic protein from Pae. polymyxa showed strong antifungal activity against phytopathogenic fungus Pen. expansum. This strain HT16 and the antifungal metabolite are therefore strong candidates for the biocontrol of phytopathogens in agriculture.
