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The aim of this study was the isolation and characterization of thermophilic bacteria from hot springs in Jordan. Ten isolates were characterized by morphological, microscopic, biochemical, molecular, and physiological characteristics. Sequencing of the 16S rDNA of the isolates followed by BLAST search revealed that nine strains could be identified as Bacillus licheniformis and one isolate as Thermomonas hydrothermalis. This is the first report on the isolation of Thermomonas species from Jordanian hot springs. The isolates showed an ability to produce some thermostable enzymes such as amylase, protease, cellulose, gelatins, and lecithin. Moreover, the UPGMA dendrogram of the enzymatic characteristics of the ten isolates was constructed; results indicated a high phenotypic diversity, which encourages future studies to explore further industrial and environmental applications.

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Actinobacterial isolates randomly obtained on nitrogen-free BAP medium from surface sterilized root nodules of Alnus glutinosa, Casuarina glauca and Elaeagnus angustifolia sampled from fields were reported. They were assigned on the basis of partial 16S rRNA sequences to Micromonospora, Nocardia and Streptomyces genera. The isolates have been screened for hydrolytic activities, indole acetic acid (IAA) and siderophores production, phosphate solubilization and antagonistic activities. Results suggest putative traits as plant growth promoting bacteria proprieties of the isolates that occur in unique association in root nodules of the three analysed actinorhizal host species.

The aim of this study was to assess the potential of newly isolated yeast strains Schwanniomyces etchellsii M2 and Candida pararugosa BM24 to produce yeast biomass on olive mill wastewater (OMW). Maximum biomass yield was obtained at 75% (v/v) OMW, after 96 h of incubation at 30 °C and 5% (v/v) inoculum size. The optimal carbon/nitrogen (C/N) ratio was in the range of 8:1 to 10:1, and ammonium chloride was selected as the most suitable nitrogen source. Under these conditions, a maximum biomass production of 15.11 and 21.68 g L(-1) was achieved for Schwanniomyces etchellsii M2 and Candida pararugosa BM24, respectively. Proteins were the major constituents of yeast cells (35.9-39.4% dry weight), lipids were 2.8-5% dry weight, and ash ranged from 4.8 to 9.5 % dry weight. Besides biomass production, yeast strains were also able to reduce toxicity and polluting parameter levels of the spent OMW-based medium. The practical results presented show that pH rose from initial value of 5.5 to 7.24-7.45 after fermentation. Approximately 23.1-41.4% of the chemical oxygen demand (COD) and 15.4-19.2% of the phenolic compounds were removed. The removal of phenolic compounds was associated with their biodegradation and their partial adsorption on yeast cells.

The present investigation focused on screening of a new potent strain for laccase production and optimizing the process parameters to achieve the maximum enzymatic decolourization of textile azo dye Congo red. Seven hydrocarbonoclastic bacterial strains were selected as positive in laccase production in solid medium using 2,6 dimethoxyphenol as an enzyme activity indicator. The best enzyme producer Pseudomonas extremorientalis BU118 showed a maximum laccase activity of about 7000 U/L of wheat bran under solid-state conditions. The influence of different concentrations of dye, enzyme, salt and various incubation times on Congo red decolourization was studied using response surface methodology to find the optimum conditions required for maximum decolourization by P. extremorientalis laccase. The enzyme exhibited a remarkable colour removal capability over a wide range of dye and salt concentrations. The above results show the potential use of this bacterial laccase in the biological treatment of the textile effluent.

In order to define an efficient pre-treatment of Olive Oil Mill Wastewater (OOMW) to overcome major obstacles to biological treatment, various organic and mineral coagulants have been tested. In particular, the application of quicklime until a pH around 12 - 12.4 was reached, allowed the reduction of almost 37% of the initial COD, and approximately 88% and 71% of the colour and phenolic content of the waste. Hence, further biological treatments with an adapted aerobic consortium (AC) and a white rot fungus (WRF) strain were improved. The WRF Coriolopsis polyzona was more efficient than AC to reduce colour and polyphenols when the waste was prior diluted or pre-treated; however, it was less effective in COD removal. The combined treatment: lime - AC of OOMW having initial COD of 102 g l(-1) led to the elimination of about 77, 91 and 63%, of the COD, phenols and colour, respectively. Interestingly, the opposite combination AC - lime permitted better COD, phenols and colour reduction to respectively, 21, 11 and 11% of the initial values. This latter condition is technically recommended since only one step separation was needed and no pH correction was necessary before undergoing aerobic treatment. Moreover, the process would produce a sludge potentially rich in organic matter, and consequently, useful as an agricultural amendment or/and as an additive in animal nutrition.