TCA Cycle Replenishing Pathways in Photosynthetic Purple Non-Sulfur Bacteria Growing with Acetate

Purple non-sulfur bacteria (PNSB) are anoxygenic photosynthetic bacteria harnessing simple organic acids as electron donors. PNSB produce a-aminolevulinic acid, polyhydroxyalcanoates, bacteriochlorophylls a and b, ubiquinones, and other valuable compounds. They are highly promising producers of molecular hydrogen. PNSB can be cultivated in organic waste waters, such as wastes after fermentation. In most cases, wastes mainly contain acetic acid. Therefore, understanding the anaplerotic pathways in PNSB is crucial for their potential application as producers of biofuels. The present review addresses the recent data on presence and diversity of anaplerotic pathways in PNSB and describes different classifications of these pathways.

The Great Oxygenation Event as a consequence of ecological dynamics modulated by planetary change

The Great Oxygenation Event (GOE), ca. 2.4 billion years ago, transformed life and environments on Earth. Its causes, however, are debated. We mathematically analyze the GOE in terms of ecological dynamics coupled with a changing Earth. Anoxygenic photosynthetic bacteria initially dominate over cyanobacteria, but their success depends on the availability of suitable electron donors that are vulnerable to oxidation. The GOE is triggered when the difference between the influxes of relevant reductants and phosphate falls below a critical value that is an increasing function of the reproductive rate of cyanobacteria. The transition can be either gradual and reversible or sudden and irreversible, depending on sources and sinks of oxygen. Increasing sources and decreasing sinks of oxygen can also trigger the GOE, but this possibility depends strongly on migration of cyanobacteria from privileged sites. Our model links ecological dynamics to planetary change, with geophysical evolution determining the relevant time scales.

Co-Culture Anoxygenic Photosynthetic Bacteria With Bacillus sp. Isolated From Hanura Beach Against Vibrio sp.

A mangrove forest ecosystem is a place where many special Bacillus sp. found. This study aims to obtain Bacillus sp. isolates that can inhibit the growth of Vibrio sp. This study was conducted by selecting 77 Bacillus sp. isolates from the Hanura mangrove forest area. In addition, selected bacteria were tested for salt stress, pH stress, pathogenicity test, and antibiotic susceptibility test. Selected isolates were cultivated together with Vibrio sp. for 7 days. Bacillus sp. and Vibrio sp. cultured again with the addition of anoxygenic photosynthetic bacteria for 4 days. From the results of the initial selection, 4 isolates could inhibit the growth of Vibrio sp. The final results showed that Bacillus IL2K8 isolates were known to inhibit the growth of Vibrio sp., can grow at salinity 0%, 3%, 6% and pH 7 and pH 10. IL2K8 isolates are not pathogenic, resistant to amplicin antibiotics, streptomycin, nalidixic acid, and chloramphenicol but sensitive to trimethoprim antibiotics. In the joint culture of liquid media IL2K8 together with Anoxygenic Photosynthetic Bacteria (APB) isolates IL2K8 can inhibit the growth of Vibrio sp.

Whole-Genome Sequence of a Unique Elioraea Species Strain Isolated from a Yellowstone National Park Hot Spring

The genus Elioraea has only one species characterized microbiologically and two genomes sequenced. We have sequenced the genome of a unique Elioraea strain isolated from Yellowstone National Park and found it to be a distinct new species. Elioraea is suggested to be a member of the aerobic anoxygenic photosynthetic bacteria.

Effects of Magnetic Fields and Metal Ions (Cu, Pb, Al and Fe) on Growth of Anoxygenic Photosynthetic Bacteria (APB)

Bakteri Fotosintetik Anoksigenik (BFA) memiliki sifat yang menguntungkan diantaranya sebagai kandidat probiotik, biofertilizer, agen bioremediasi dan mampu menurunkan konsetrasi H2S di perairan. Namun demikian BFA pun memiliki kelemahan yaitu pertumbuhannya lambat. Interaksi ion logam dan paparan medan magnet diketahui dapat meningkatkan aktivitas enzim dan meningkatkan laju pertumbuhan. Penelitian ini bertujuan untuk mengetahui pengaruh ion logam dan paparan medan magnet terhadap pertumbuhan BFA. Isolat BFA AM hasil isolasi dari akar mangrove diuji pengaruhnya terhadap ion logam dalam media sea water complete (SWC). Ion logam yang diujikan adalah Cu, Pb, Al dan Fe dengan konsentrasi yang berbeda. Ion logam dipapar medan magnet 0,2 mT selama 10 menit sebelum ditambahkan ke media. Hasil penghitungan sel menunjukkan bahwa ion logam baik yang dipapar medan magnet dan tanpa dipapar medan magnet tidak berpengaruh terhadap pertumbuhan isolat BFA AM, namun ion logam dalam media SWC mempengaruhi pola spektra isolat BFA AM.