Identification of diacetonamine from soybean curd residue as a sporulation-inducing factor toward Bacillus spp.

Under bioassay-guided investigation, a sporulation-inducing factor (SIF) toward Bacillus spp. was searched for in methanol (MeOH) extracts of soybean curd residues, and diacetonamine (1) was identified as the active compound. SIF was first isolated as a monoacetylated derivative (2, 4.1 mg from 655 g soybean curd residues), and its chemical structure was elucidated by field desorption mass spectrometry, electron ionization mass spectrometry, and nuclear magnetic resonance (NMR) analyses. After 48-h incubation, 40 mu M diacetonamine hydrochloride (1b) exhibited sporulation-inducing activity with 35% sporulation frequency toward a Bacillus amyloliquefaciens wild-type strain (AHU 2170), whereas 40 mu M diacetone acrylamide (3) showed 99% sporulation induction, which was much higher than that of 1b. Although Bacillus megaterium NBRC 15308 was sporulated by the treatment with 400 mu M 1b with 36 and 70% sporulation frequency after 72-and 96-h incubation respectively, 3 at the same concentration showed only 2% sporulation after 72-h incubation. Hence, diacetonamine (1) was characterized as a genuine SIF from soybean curd residues, but it was uncertain whether 1 is a natural product or an artifact. Spores of B. amyloliquefaciens induced by 1b survived after treatment with heating at 95 degrees C for 10 min, also suggesting that 1 is genuine SIF in soybean curd residue. As sporulation induction is likely linked to activation of antibiotic production in some spore-forming Firmicutes bacteria, compound 1 would be a possible chemical tool to develop an effective fermentation technology in Bacillus species

Extreme High Yield of Tropical Rice Grown Without Fertilizer on Acid Sulfate Soil in South Kalimantan, Indonesia

Extreme High Yield of Tropical Rice Grown Without Fertilizer on Acid Sulfate Soil in South Kalimantan, Indonesia (E Purnomo, Y Hashidoko, T Hasegawa and M Osaki): Local rice arieties are commonly grown by the farmers located in acid sulfate soil area of South Kalimantan. In South Kalimantan, more than 100 local rice varieties can be found. In 1999, a farmer found one hill (with 5 tillers) rice plant near a canal, later called Padi Panjang. The rice had panicle length of 50 cm. The panicle length of common local rice varieties are 25 cm. Since the finding, the farmer multiplied the seed for 3 years to get a reasonable amount of seeds for nearby farmers to use. In 2004, there were 25 farmers grow the Padi Panjang by themselves. Their paddocks are widely spread out in Aluh-Aluh and Gambut districts. We take this opportunity to investigate yield variation of the Padi Panjang that may be affected by soil properties variability. Ten paddocks out of the 25 paddock were selected. At harvest time (in July-August), we measured the rice yield and collected soil sample from the 10 paddocks. We found that the soil condition in the selected paddocks were marginally suitable for growing improved rice. Without fertilizer, however, the rice yield varied from 3.21 to 8.09 Mg ha-1. We also observed that the rice yield variations associated with tillers number. We did not find any correlation between rice yields with some selected soil properties, except it was observed that the tillers number was negatively correlated with soil electrical conductivity (EC). The extreme yield of Padi Panjang might be explained the involvement of N fixing bacteria and P solubilizing bacteria, large rooting system and the ability of Padi Panjang root in modifying the rhizosphere soil

Isolasi dan Respons Tumbuh Cendawan Mutualistik Akar pada Beberapa Tanaman Pangan dan Kehutanan

The study aims to isolate and test the effectiveness of mutualistic root symbiont fungi isolates from the roots of rubber plants grown in marginal acidic soil plantations in increasing the growth of food crops and forestry plants. The fungal were isolated by root surface sterilization methods. We obtained 19 fungal isolates consisting of 8 genera, namely Alternaria, Aspergillus, Cladosporium, Curvularia, Fusarium, Penicillium Paecilomyces, Trichoderma, and mycelia sterilia. All isolates were subjected to a pathogenicity test on the Centrosema pubescens plant. Five out of the 19 fungal isolates increased plant growth and showed no disease symptoms, and the Aspergillus section Nigri FKK 3 isolate showed the best response. The isolate was further analyzed to assess the growth response of food crops (rice and corn) and forestry plants (Acacia auriculiformis and Paraserianthes falcataria). The treatments consisted of 3 phosphate (P) concentrations, namely 20%, 50%, and 100% of the recommended field applications. The combination of mutualistic fungal inoculation of Aspergillus section Nigri FKK 3 and 50% P concentration exhibited the highest biomass growth response compared to other treatments. This finding can provide basic information for developing fungal-based fertilizers to increase the productivity of food crops and forestry plants on sub-optimal land.   Keywords: food crops, phosphate fertilizer, forestry trees, plant growth improvement, root mutualistic fung

Base-Mediated One-Pot Synthesis of Aliphatic Diazirines for Photoaffinity Labeling

Aliphatic diazirines have been widely used as prominent photophores for photoaffinity labeling owing to their relatively small size which can reduce the steric effect on the natural interaction between ligands and proteins. Based on our continuous efforts to develop efficient methods for the synthesis of aliphatic diazirines, we present here a comprehensive study about base-mediated one-pot synthesis of aliphatic diazirines. It was found that potassium hydroxide (KOH) can also promote the construction of aliphatic diazirine with good efficiency. Importantly, KOH is cheaper, highly available, and easily handled and stored compared with the previously used base, potassium tert-butoxide (t-BuOK). Gram-scale study showed that it owned great advantages in being used for the large-scale production of aliphatic diazirines. This protocol is highly neat and the desired products can be easily isolated and purified. As the first comprehensive study of the base-mediated one-pot synthesis of aliphatic diazirines, this work provided good insight into the preparation and utilization of diazirine-based photoaffinity labeling probes

Studies on Functional Bacteria of Indonesian Tropical Forest Plants for Biorehabilitation of Degraded Lands

Forest degradations have left vast amount of damaged and abandoned lands in Indonesia. In this paper, we present our approaches in rehabilitation of adverse soils using functional bacteria isolated from plant species of Indonesian tropical rain forests. For these purposes, we collected bacteria from various bio-geo-climatically different forests and conducted bioassays to test these bacterial abilities in improving plant growth. Repeated seedling-based studies on Shorea spp., Alstonia scholaris, Acacia crassicarpa, and Agathis lorantifolia have revealed that many bacteria were able to promote plant growth at early stage in the nursery. Various plant responses towards inoculations suggested that although forest soils maintain highly diverse and potent bacteria, it is necessary to select appropriate approaches to obtain optimum benefits from these plant-bacteria interactions. Our ideas and futures studies for further management of these plant- bacteria interactions for biorehabilitation are also discussed

Ecochemical Studies of Interrelationships between Epiphytic Bacteria and Host Plants via Secondary Metabolites

The plant surface, which is representative of the phyllopane and rhizoplane, is a characteristic habitat for microorganisms. In this review, the ecological roles of phytoepiphytic bacteria will be described. The phylloplane and rhizoplane, which are adjacent to the atmosphere and soil sphere respectively, accumulate topically and /or selectively release secondary metabolites that are specific to the plant genera and species which reside within these regions. Some epiphytes have abilities to decarboxylate xenobiotic phenolic acids that have accumulated in the plant tissues and surface as a majority of such secondary metabolites. In physicochemically stressed soil, rhizosphere microflora often remedy such microenvironments within the rhizosphere in order to assist in the survival of the host, and some of the microfloral compositions behave as if they were symbionts. Specifically, some Sphingomonas spp., which are frequently isolated from the rhizosphere of acidic soil-tolerant plants in tropical zones, make possible the development of a rhizo-biocomplex. In this review, the possibility of rhizosphere regulation utilizing such a rhizo-biocomplex is discussed