Nodulation and subsequent nitrogen fixation by soybean [Glycine max (L.) Merr.] plants are inhibited by low root zone temperatures (RZTs). Plant growth promoting bacteria can help overcome these deleterious effects. Three Bacillus strains, B. subtilis NEB4 and NEB5 and B. thuringiensis NEB17, were isolated from inside the nodules of vigorous field‐grown soybean plants in 1998, and were shown to have plant growth promoting activity on pouch‐grown soybean plants under greenhouse conditions. To test their ability to improve soybean nodulation and growth under low RZTs, these strains were coinoculated onto soybean plants, with Bradyrhizobium japonicum, under greenhouse conditions at RZTs of 25, 17, and 15°C, and under field conditions in a short growing season area. In all cases, the experiments were conducted with soybean cultivar OAC Bayfield. All the three Bacillus strains enhanced soybean nodulation and growth in greenhouse and field experiments. Coinoculation with NEB17 provided the largest and most consistent increases in nodule number, nodule weight, shoot weight, root weight, total biomass, total nitrogen, and grain yield. The other two strains provided positive responses in only 1 of the 2 yr of field‐testing. Thus, B. thuringiensis NEB17 would be suitable for use as a plant growth promoting bacterial strain in soybean production systems in short growing season regions.

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Aims:  The aim of this study was to identify and characterize a compound produced by the plant growth promoting bacterium, Bacillus thuringiensis non‐Bradyrhizobium Endophytic Bacterium 17. Methods and Results:  The bacterial peptide was analysed and purified via HPLC. Using the disk diffusion assay this peptide inhibited the growth of 16/19 B. thuringiensis strains, 4/4 Bacillus cereus strains, among others, as well as a Gram‐negative strain Escherichia coli MM294 (pBS42). Both bactericidal and bacteristatic effects were observed on B. cereus ATCC 14579 and bactericidal effects were observed on B. thuringiensis ssp. thuringiensis Bt1267. The molecular weight of the peptide was estimated via SDS‐PAGE and confirmed with Matrix Assisted Laser Desorption Ionization Quadrapole Time of Flight mass spectrometry; its weight is 3162 Da. The peptide is biologically active after exposure to 100°C for 15 min, and within the pH range 1·00–9·25. Its activity disappeared when treated with proteinase K and protease, but not with α‐amylase or catalase. Conclusions:  We conclude that this is the first report of a bacteriocin produced by a plant growth promoting rhizobacteria (B. thuringiensis) species and have named the bacteriocin thuricin 17. Significance and Impact of the Study:  Our work has characterized a bacteriocin produced by a plant growth promoting bacterium. This strain is previously reported to increase soya bean nodulation.

generally show greater differences (Box and Ramseur, 1993). Several methods have been used to estimate root Image analysis has greatly simplified the measurement of root length (Rowse and Phillips, 1974;Richards et al., 1979; systems, allowing more detailed and accurate assessment of standard Zoon and Van Tienderen, 1990). The most widely emroot variables. However, maize (Zea mays L.) root morphology has primarily been studied in conventional hybrids. We tested the hypoth-ployed methods are based on the line intersect principle, esis that genotypes carrying the leafy trait (taller plants with more which was first devised by Newman (1966) and later leaves and greater leaf area development) would have root morpholomodified (Marsh, 1971; Tennant, 1975). Because this gies differing from those of conventional maize hybrids. A 3 ϫ 3 method relies on visual counting of grid line-root interfactorial experiment was arranged in a randomized complete block cepts, it can be time consuming and prone to inaccuracy, design with three blocks, three fertilization levels (0, 127.5, and 255 especially when measuring samples with a large proporkg N ha Ϫ1 as NH 4 NO 3 ), and three maize genotypes [leafy reduced tion of fine roots (Smit et al., 1994). However, the line stature (LRS), leafy normal stature (LNS), and a conventional comintercept method improved root measurement and, in mercial hybrid Pioneer 3905 (P3905)]. The genotypes were selected particular, reduced the time required for analysis comfor their contrasting canopy and root architectures. Plants were grown pared with simpler, manual methods. For example, the in 63-L plastic containers, and the roots were measured at the silking stage (80 d from emergence) by scanner-based image analysis. In

In our previous study, we have found that persimmon, guava, and sweetsop owned considerably high antioxidant activity and contained high total phenolic contents as well. In order to further supply information on the antibacterial and antioxidant activity of these three tropic fruits, they were extracted by 80% methanol. We then examined the extractions about their phenolic compounds and also studied the extractions and phenolic contents about their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against twelve targeted pathogens including 8 standard strains (Staphylococcus aureus, Bacillus cereus, Staphylococcus epidermidis, Monilia albican, Escherichia coli, Salmonella typhimurium, Shigella flexneri, and Pseudomonas aeruginosa) and 4 multidrug-resistant strains (methicillin-resistant Staphylococcus aureus, ESBLs-producing Escherichia coli, carbapenems-resistant Pseudomonas aeruginosa, and multidrug-resistant Acinetobacter baumannii), which are common and comprehensive in clinic. We also employed two ways, that is, FRAP and TEAC, to evaluate their antioxidant activities, using ultraviolet and visible spectrophotometer. Our study indicated that the three tropical fruits possessed obvious antioxidant and antibacterial activity, which supported the possibility of developing the fruits into new natural resource food and functional food as well as new natural antimicrobial agent and food preservatives. Moreover, phenolic compounds detected in the fruits could be used as a potential natural antibacterial agent and antioxidant.