PENGARUH EKSTRAK DAUN SERAI (Cymbopogon citrates) SEBAGAI BAHAN ALAMI SABUN DALAM MENURUNKAN ANGKA KUMAN PADA GELAS

Latar Belakang : Tanaman serai dapur (Cymbopogon citratus) mampu menghasilkan minyak atsiri dengan kadar sitronellal 30 – 45% dan geraniol 65 – 90%. Geraniol bekerja sebagai antibakteri dengan cara mengubah permeabilitas membran sel, menghilangkan ion-ion dalam sel. Minyak atsiri memiliki peran sebagai antibakteri dengan cara mengganggu proses terbentuknya membrane sel hingga tidak berbentuk sempurna. Tujuan : Mengetahui penurunan angka kuman alat makan gelas setelah penggunaan sabun pencuci alat makan dari limbah minyak jelantah dan ekstrak daun serai dan konsentrasi ekstrak daun serai pada sabun pencuci alat makan dari minyak jelantah yang paling efektif sebagai sabun dalam menurunkan angka kuman. Metode : Penelitian ini adalah eksperimental (Quasi Experiment) dengan pendekatan Nonequivalent Control Group Design. Jumlah obyek penelitian sebanyak 24 buah gelas. Variabel bebas penelitian ini adalah konsentrasi ekstrak daun serai 20,67%, 24% dan 27,33%. Variabel terikat pada penelitian ini adalah angka kuman gelas. Hasil : Penurunan angka kuman gelas dengan sabun ekstrak daun serai konsentrasi 20,67% sebanyak 57,5 CFU/cm2 atau 60,2%, konsentrasi 24% sebesar 70,7 CFU/cm2 atau 75,45%, dan konsentrasi 27,33% sebesar 83,2 CFU/cm2 atau 91%. Berdasarkan hasil uji One Way Anova didapatkan p-value sebesar 0,505 (Sig. >0,05). Kesimpulan : Secara statistik ketiga konsentrasi tidak ada pengaruh yang bermakna dalam menurunkan angka kuman gelas, secara deskriptif dan statistik konsentrasi 27,33% menurunkan angka kuman tertinggi. Kata Kunci : sabun, minyak jelantah, ekstrak daun serai, angka kuman gela

Cryptic Polyketide Synthase Genes in Non-Pathogenic Clostridium SPP

Modular type I polyketide synthases (PKS) produce a vast array of bacterial metabolites with highly diverse biological functions. Notably, all known polyketides were isolated from aerobic bacteria, and yet no example has been reported for strict anaerobes. In this study we explored the diversity and distribution of PKS genes in the genus Clostridium. In addition to comparative genomic analyses combined with predictions of modular type I polyketide synthase (PKS) gene clusters in sequenced genomes of Clostridium spp., a representative selection of other species inhabiting a variety of ecological niches was investigated by PCR screening for PKS genes. Our data reveal that all studied pathogenic Clostridium spp. are devoid of putative PKS genes. In stark contrast, cryptic PKS genes are widespread in genomes of non-pathogenic Clostridium species. According to phylogenetic analyses, the Clostridium PKS genes have unusual and diverse origins. However, reverse transcription quantitative PCR demonstrates that these genes are silent under standard cultivation conditions, explaining why the related metabolites have been overlooked until now. This study presents clostridia as a putative source for novel bioactive polyketides

Bacterial associations reveal spatial population dynamics in Anopheles gambiae mosquitoes

The intolerable burden of malaria has for too long plagued humanity and the prospect of eradicating malaria is an optimistic, but reachable, target in the 21st century. However, extensive knowledge is needed about the spatial structure of mosquito populations in order to develop effective interventions against malaria transmission. We hypothesized that the microbiota associated with a mosquito reflects acquisition of bacteria in different environments. By analyzing the whole-body bacterial flora of An. gambiae mosquitoes from Burkina Faso by 16 S amplicon sequencing, we found that the different environments gave each mosquito a specific bacterial profile. In addition, the bacterial profiles provided precise and predicting information on the spatial dynamics of the mosquito population as a whole and showed that the mosquitoes formed clear local populations within a meta-population network. We believe that using microbiotas as proxies for population structures will greatly aid improving the performance of vector interventions around the world

Vitamin E deficiency and risk of equine motor neuron disease

© 2007 Mohammed et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Widespread Occurrence of Secondary Lipid Biosynthesis Potential in Microbial Lineages

Bacterial production of long-chain omega-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), is constrained to a narrow subset of marine γ-proteobacteria. The genes responsible for de novo bacterial PUFA biosynthesis, designated pfaEABCD, encode large, multi-domain protein complexes akin to type I iterative fatty acid and polyketide synthases, herein referred to as “Pfa synthases”. In addition to the archetypal Pfa synthase gene products from marine bacteria, we have identified homologous type I FAS/PKS gene clusters in diverse microbial lineages spanning 45 genera representing 10 phyla, presumed to be involved in long-chain fatty acid biosynthesis. In total, 20 distinct types of gene clusters were identified. Collectively, we propose the designation of “secondary lipids” to describe these biosynthetic pathways and products, a proposition consistent with the “secondary metabolite” vernacular. Phylogenomic analysis reveals a high degree of functional conservation within distinct biosynthetic pathways. Incongruence between secondary lipid synthase functional clades and taxonomic group membership combined with the lack of orthologous gene clusters in closely related strains suggests horizontal gene transfer has contributed to the dissemination of specialized lipid biosynthetic activities across disparate microbial lineages