Biosorption of nickel (II) from effluent of electroplating industry by immobilized cells of Bacillus species

In this study, Ni (II) biosorption capacity of immobilized cells of Bacillus sp. was investigated. Biosorption of Ni (II) was carried out in batch experiments and the important environmental conditions were optimized. The uptake of metal was rapid, and equilibrium was attained within 270 min. Bacillus strains (ten cultures) were isolated from nickel electroplating effluent by heat shock method. These isolates were grown up in nutrient broth supplemented with Ni (II)(50 mg/L). The culture, exhibiting maximum biosorption capacity (q^max: 118 mg/g), was selected and labeled Bacillus Bio‐4. In order to develop an economical biosorption process cell mass of Bacillus, Bio‐4 was immobilized in Na‐alginate. It was concluded from the results that biosorption of nickel is highly dependent on the type of sorbent and experimental conditions employed. Our results demonstrate that 6.0 mg immobilized cells (18 mg cell biomass in 3.0 mL of 1% Na alginate) had a maximum biosorption capacity of 113 mg Ni(II) per liter of suspension at pH 8.0, 100 rpm and 25°C. The Ni (II) removal was estimated to be 97.4%.     

Structure and biochemistry of the spore surface ofSyncephalastrum racemosum

Freeze-fracture studies have revealed a surface layer of rodlets on spores ofSyncephalastrum racemosum. Rodlets can be removed by treatment with alkali. Analysis of the extracts indicated the presence of a glycoprotein with a molecular weight of approximately 12,000.     

Changes in the organisation of surface rodlets during germination ofSyncephalastrum racemosum sporangiospores

Summary Dormant sporangiospores ofSyncephalastrum racemosum have a regular pattern of rodlets on their surface. During the spherical growth phase of spore germination these rodlets become displaced and areas free from rodlets appear. At the time of germ tube emergence the rodlets remain on the spherical portion of the spore whilst the germ tube has a smooth surface.     

An ultrastructural and autoradiographic study of stipe elongation inAgaricus bisporus

Summary The cytology and ultrastructure of different cell types in the elongating stipe of the basidiomyceteAgaricus bisporus are described. Light and electron microscope autoradiography are used to locate the sites of synthesis of chitin.     

Ultrastructure of the septum inCandida albicans

The ultrastructure of the septum in the mycelial phase of the dimorphic fungusCandida albicans has been studied both in thin sections of fixed material and in shadow casts of the chemically purified chitinous wall layer. The septum has a 25-nm central micropore which would not allow the passage of nuclei or mitochondria, thus delimiting these organelles within the mycelial compartments without preventing cytoplasmic continuity.