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Background Plant growth-promoting rhizobacteria (PGPR) are known to improve plant growth and are used as biofertilizers, thanks to their numerous benefits to agriculture such as phosphorus solubilization and phytohormone production. In this paper, four rhizospheric bacteria (Phyllobacterium sp., Bacillus sp., Agrobacterium sp., and Rhizobium sp.) isolated from surface-sterilized root nodules of Acacia cyanophylla were tested for their ability to solubilize inorganic phosphate and to produce indole-3-acetic acid (IAA) under laboratory conditions. Then, the best IAA producer (Rhizobium sp.) was selected to test optimized conditions for IAA production. Finally, the effect of the four strains on plant growth for A. cyanophylla was evaluated in vivo. Results The results showed that the totality of the tested isolates had solubilized inorganic phosphate (P) in both NBRIP (National Botanical Research Institute Phosphate) and PVK (Pikovskaya) media. Bacillus sp. was a high P-solubilizer and showed maximum solubilization in PVK (519 μg ml-1) and NBRIP (782 μg ml-1). The optimization of maximum phosphate solubilization was done using different sources of carbon (1%) and nitrogen (0.1%). Glucose and ammonium sulfate were selected to be the best carbon and nitrogen source for phosphate solubilization by all tested strains, except for Phyllobacterium sp., which recorded the highest phosphate solubilization with ammonium nitrate. The IAA production by the tested strains indicated that Rhizobium sp. produced the highest amount of IAA (90.21 μg ml-1) in culture media supplemented with L-tryptophan. The best production was observed with L-Trp concentration of 0.2% (116.42 μg ml-1) and at an initial pH of 9 (116.07 μg ml-1). The effect of NaCl on IAA production was tested at concentrations of 0 to 5% and the maximum production of  89.43 μg ml-1 was found at 2% NaCl. The extraction of crude IAA from this strain was done and purity was confirmed with Thin Layer Chromatography (TLC) analysis. A specific spot from the extracted IAA production was found to correspond with a standard spot of IAA with the same Rf value. Finally, the tested PGPR demonstrated growth stimulatory effects on Acacia cyanophylla seedlings in vivo, with a great increase of shoots’ and roots’ dry weights, and shoot length compared to control. The rhizobacterial isolates were identified by 16S rDNA sequence analysis as Agrobacterium sp. NA11001, Phyllobacterium sp. C65, Bacillus sp. CS14, and Rhizobium sp. V3E1. Conclusion This study highlights the importance of the use of phosphate solubilizing and IAA producer microorganisms as biofertilizers to increase crop yields. The studied strains showed a significant phosphate solubilization potential and IAA production. The use of selected strains as inoculants would be interesting, in particular with a view of promoting sustainable agriculture. However, further studies to verify the efficacy of the best isolates in situ is certainly required.

Background: The production of indole-3-acetic acid (IAA) is an essential tool for rhizobacteria to stimulate and facilitate plant growth. For this, eighty rhizobial bacteria isolated from root nodules of Acacia cyanophylla grown in different regions of Morocco were firstly screened for their ability to produce IAA. Then, IAA production by a combination of isolates and the inoculation effect on the germination of Acacia cyanophylla seeds was studied using the best performing isolates in terms of IAA production. The best IAA producer bacterial isolate (I69) was selected to optimize IAA production using response surface methodology based on the central composite design. Results: Results showed that the majority of tested isolates were able to produce IAA with a relatively higher concentration of 135 μg/ml for the isolate I69, followed by isolates I22 and I75 with respective concentrations of 116 μg/ml and 105 μg/ml IAA. The IAA production and the seed germination rate were relatively increased by the synergistic effect of I69 and I22. Later, response surface methodology was used to determine optimal operating conditions leading to IAA production optimization. Thus, an incubation temperature of 36°C, a pH of 6.5, an incubation time of 1 day, and respective tryptophan and NaCl concentrations of 1 g/l and 0.1 g/l were optimal parameters leading to 166 μg/ml IAA which was the maximal produced concentration. Conclusion: The present study highlighted that IAA-producing rhizobacteria could be harnessed to improve plant growth. Furthermore, their production can be easily controlled using response surface methodology, which represents a very useful tool for optimization.

An enrichment and isolation program for new ethanol‐producing thermotolerant yeasts as well as a screening program of some known thermotolerant strains resulted in the selection of several strains capable of growth at 40–43°C. Among these strains four grew and fermented sugar cane molasses at 43°C under batch conditions with sugar‐conversion efficiencies >94% and ethanol concentrations 6.8–8.0% (w/v). The two best‐performing strains, a Saccharomyces cerevisiae F111 and a Kluyveromyces marxianus WR12 were used in eight 87.5 m3 fermentation runs (four using each strain) for industrial ethanol production in an Egyptian distillery using sugar cane molasses. Mean ethanol production was 7.7% and 7.4% (w/v), respectively, with an added advantage of cooling elimination during fermentation and higher ethanol yields compared to the distillery's S. cerevisiae SIIC (ATCC 24855) strain in use. The isolate S. cerevisiae F111 was subsequently adopted by the distillery for regular production with significant economical gains and water conservation. © 2000 John Wiley & Sons, Inc. Biotechnol Bioeng 68: 531–535, 2000.

Leishmaniasis diseases are endemic in Morocco. An entomological survey was conducted in Aichoun locality for 1 year from September 2013 to August 2014. The objective of this study was to investigate the sand fly fauna, mainly the species composition and the monthly species prevalence in accordance with bioclimate factors. Sand flies were collected twice a month, using sticky traps and CDC light traps. During a one-year study, 4472 specimens of sand fly were caught (72.56% male/22.44% female) that were composed of seven species divided into two genera: Phlebotomus (99.46%) and Sergentomyia (0.53%). Ph. sergenti was the most prevalent species (46.64%), followed by Ph. perniciosus (38.19%), Ph. longicuspis (9.32%), Ph. papatasi (5.23%), and Ph. ariasi (0.06%). The genus Sergentomyia was even less frequent. The population dynamics showed a bimodal trend with two peaks: the first one in October (12.03% of specimens) and the second in June (27.92% of specimens). The study of the effects of climatic factors in the study area showed a link between the dynamics of sand flies and the variation of these parameters (temperature and relative humidity). During the period between November and March, the sand flies were absent. The highest prevalence of sand flies was recorded in June when the temperature and relative humidity values reached, respectively, 25.8°C and 42%. The minimum number of specimens was collected in September with an average temperature of 23.19°C and relative humidity of 57.4%. Statistical analysis with principal component analysis has shown a strong positive correlation between temperature parameters and the seasonal distribution of sand flies. The climatic factor of relative humidity has been judged of being negatively correlated. The wind speed does not have any impact on the relative abundance of all species. Within this context, the results will be useful for the development of a monitoring program to better manage the operations and evaluate their effectiveness.