Improvement of Zn (II) and Cd (II) Biosorption by Priestia megaterium PRJNA526404 Isolated from Agricultural Waste Water

Abstract

Heavy metals are considered as dangerous pollutants even in relatively low concentrations. Biosorption is an ecofriendly technology that uses microbial biomasses for adsorbing heavy metals from wastewater on their surfaces based on physicochemical pathways. Ten agricultural wastewater samples were collected from different sites in Sohag Governorate, Egypt. One hundred and nineteen zinc and cadmium-resistant bacterial isolates were recovered from the water samples. Interestingly, the isolate R1 was selected as the most resistant to Zn2+ and Cd2+. This isolate was morphologically and biochemically characterized and identified by sequencing of 16S rRNA gene as Priestia megaterium, and then deposited in the GenBank database under the accession number PRJNA526404. Studying the effects of pH and contact time on the biosorption process revealed that the maximum biosorption was achieved within 50 min at pH 7 and 8 for Zn2+ and Cd2+, respectively, by the living and lyophelized biomass of Priestia megaterium PRJNA526404. The preliminary characterization of the main chemical groups present on the cell wall, which are responsible for heavy metal biosorption, was performed by Infrared analysis (IR). Kinetics studies revealed that data were fitted towards the models hypothesized by Langmuir and Freundlich isotherm equations. The maximum capacity values (qmax) for biosorption of zinc and cadmium reached by using living and lyophelized biomass were 196.08; 227.27 and 178.57; 212.777 mg/g, respectively, and it was indicated that lyophilization improved efficiency of the biomass to heavy metals compared to living cells. The results indicated that Priestia megaterium PRJNA526404 had good application prospect in cadmium and zinc water remediation.

The Remediation of Dysprosium-Containing Effluents Using Cyanobacteria Spirulina platensis and Yeast Saccharomyces cerevisiae

“…Dy 3+ is the major form of dysprosium at pH values between 1.0 and 4.0, while at higher pH values, other species such as Dy(OH) 2+ , Dy(OH) 2 + , and Dy(OH) 3 are formed [ 5 , 36 ]. The decrease in dysprosium removal at higher pH values can be explained by the formation of Dy(OH) 3 , which inhibits the biosorption process [ 37 ]. Thus, further experiments were performed at pH 4.0.…”

“…The highest dysprosium adsorption was accomplished after 60 min, reaching 66% for spirulina and 85% for yeast. The fast dysprosium ion biosorption at the beginning of the reaction is explained by the availability of a large number of binding sites on the biosorbent surface [ 39 , 40 ], and its lowering at the next stage is associated with the saturation of metal binding sites and equilibrium attainment [ 37 ]. It is believed that fast metal ion removal in the first stage is mainly associated with surface adsorption, while in the second stage (the slow one), gradual adsorption is dominant [ 41 ].…”

“…The fast dysprosium ion biosorption at the beginning of the reaction is explained by the availability of a large number of binding sites on the biosorbent surface [39,40], and its lowering at the next stage is associated with the saturation of metal binding sites and Dy 3+ is the major form of dysprosium at pH values between 1.0 and 4.0, while at higher pH values, other species such as Dy(OH) 2+ , Dy(OH) 2 + , and Dy(OH) 3 are formed [5,36]. The decrease in dysprosium removal at higher pH values can be explained by the formation of Dy(OH) 3 , which inhibits the biosorption process [37]. Thus, further experiments were performed at pH 4.0.…”

“…The equilibrium of dysprosium biosorption onto spirulina and yeast biomass was examined by applying nonlinear forms of Langmuir and Freundlich isotherm models (Figure 2). equilibrium attainment [37]. It is believed that fast metal ion removal in the first stage is mainly associated with surface adsorption, while in the second stage (the slow one), gradual adsorption is dominant [41].…”

Draft genome sequence of Priestia megaterium AB-S79 strain isolated from active gold mine

“…P. megaterium members can also be found in wine, honey, fish, raw meats, seawater, the human oral cavity, and plant endophytic zones ( 5 – 7 ). P. megaterium has applications in certain bioremediation, biosorption, and bioaugmentation studies ( 8 – 10 ).…”