Production of Soluble and Functional Anti-TNF-α Fab' Fragment in Cytoplasm of E. coli: Investigating the Effect of Process Conditions on Cellular Biomass and Protein Yield Using Response Surface Methodology

The Protein Journal - With the increasing dominance of monoclonal antibodies (mAbs) in the biopharmaceutical industry and smaller antibody fragments bringing notable advantages over full-length...     

Influence of plant-growth-promoting bacteria on germination,growth and nutrients’ uptake of Onobrychis sativa L. under drought stress

The study was conducted to investigate the effect of growth-promoting bacteria (Azotobacter vinelandii?=?A, Pantoea agglomerans?+?P. putida?=?P, combined A?+?P, control) on the germination, growth and nutrient uptake of Onobrychis sativa L. under drought stress (field capacity (FC), 0.7?FC, 0.4?FC). The results showed that the highest and lowest germination rate (GR) was related to the P and control treatments in FC level, respectively. The maximum root and shoot length at the FC level was related to the treatment A. In the A?+?P treatment, the maximum shoot dry weight was measured in 0.7?FC level. The lowest root dry weight was also related to the A?+?P treatment in the FC level. Bio-fertilizers had the maximum impact in increasing the nutrients uptake in 0.7?FC and FC levels. The fertilizers in 0.7?FC and FC levels increased the plant traits and played no significant role in mitigating the effects of drought stress.     

Comparative floral development in Lamioideae (Lamiaceae): Marrubium,Phlomis, and Stachys

A comparative study of floral ontogeny and development was carried out on three genera (Marrubium L., Phlomis L., Stachys L.), representing three tribes of Lamioideae (Marrubieae, Phlomideae, Stachydeae) using epi-illumination light microscopy. The sequence of organ whorl appearance in all three genera is sepals, petals plus stamens, and carpels. Sepal appearance is reversed unidirectional starting from the adaxial side in all except Phlomis, which is unidirectional. Order of petal appearance is bidirectional in Marrubium and Stachys, and simultaneous in Phlomis. Stamens appear unidirectionally starting from the adaxial side in all except in Phlomis, which has an abaxial to adaxial unidirectional sequence. Significant developmental features distinguishing the three genera from each other include (1) weakly monosymmetric, elongated calyx tube, five-lobed corolla, divergent anthers with thecae transverse to the filament, unequally bifid stigma and ovary with glandular hairs in Marrubium; (2) actinomorphic hairy calyx, four-lobed corolla and unequally bifid stigma in Phlomis; and (3) glabrous calyx, equally bifid stigma and symmetric disc nectary in Stachys. Our results indicate some potential for floral ontogenetic features in delimiting the different tribes. The hypothetical evolutionary pathway of organogenesis sequences is discussed.     

Adhesion of Pseudomonas putida onto Palygorskite and Sepiolite Clay Minerals

Adhesion of bacteria to clay minerals is of great importance in both natural soil environments and technological applications. In the present study, equilibrium experiments along with Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX) were used to investigate the adhesion of Pseudomonas putida to the palygorskite and sepiolite clay minerals. The results showed that bacterial adhesion was rapid and reached equilibrium within 30 min. Equilibrium data showed that sepiolite has higher capacity and affinity than palygorskite for P. putida retention. Mixed FT-IR peak features of the clay minerals and P. putida were observed in the clay–bacteria complex spectra, indicating significant adhesion of P. putida to the minerals. However, some differences in the position of the individual bands were observed between infrared spectra obtained for pure bacteria or clay minerals and their corresponding clay–bacteria complexes, which are believed to be related to clay–bacteria interactions via different mechanisms. SEM/EDX analysis demonstrated fine fibrous clay particles adhered to the surface of individual P. putida cells. The results revealed rapid and close interactions of palygorskite and sepiolite with P. putida cells, which is important for better understanding the fate of bacteria in soil systems dominated by fibrous clay minerals and their practical applications in bioengineering and biotechnology.     

Synthesis, Characterization, and Theoretical and Experimental Investigations of Zinc(II)–Amino Acid Complexes as Ecofriendly Plant Growth Promoters and Highly Bioavailable Sources of Zinc

Amino acids (AA) as metal complexing agents have the ability to form relatively stable complexes with zinc (Zn) and thereby increase its availability for plants. In this study, the complexes of Zn(II), [Zn(L–L′)₂] [where L–L′ = monoanion of arginine (Arg), glycine (Gly), glutamine (Gln), histidine (His), and methionine (Met)], were synthesized and characterized by different analytical techniques. The results of elemental analysis support the formation of Zn(II)–AA complexes (ZnAAC) with a 2:1 ligand-to-metal molar ratio. The computational results indicated that the AA ligands coordinated to the Zn(II) ion via their nitrogen and oxygen atoms and support the coordination mode obtained from IR spectroscopy. For the first time, the semiempirical calculations were also performed to investigate the passive uptake of ZnAAC by root cells. The proposed transport pathway indicated that ZnAAC can pass via plant root cell wall pores without any strict hindrances. The efficacy of ZnAAC as a Zn source was evaluated for two lettuce cultivars (Lactuca sativa L., cvs. ‘Lollo Bionda’ and ‘Lollo Rossa’) grown in nutrient solution. The results confirmed the higher efficacy of ZnAAC in supplying Zn for lettuce in comparison with ZnSO₄. The synthesized ZnAAC also had a stimulating effect on root and shoot growth of both lettuce cultivars. According to the results, ZnAAC can be used as ecofriendly plant growth stimulators and sources of Zn to supply plants with readily available Zn.