Molecular cloning, expression pattern, and putative cis-acting elements of a 4-coumarate: CoA ligase gene in bamboo (Neosinocalamus affinis)

Background: 4-coumarate:CoA ligase (4CL) plays an important role at the divergence point from general phenylpropanoid metabolism to several branch pathways. Although 4CL sin higher plants have been extensively studied, little has known about the 4CL gene of bamboo. Results: In current study, a Na4CL gene putative encoding 4-coumarate:CoA ligase (4CL) and its 5’-flanking region were isolated from bamboo (Neosinocalamus affinis) by RACE-PCR and genomic DNA walker, respectively. Na4CL encodes a predicted protein of 557 amino acids, with conserved motifs of adenylate-forming enzymes. Phylogenetic analysis showed that Na4CL shared 62~85 percent identity with other known plant 4CLs, and cluster closely with some known 4CLs in monocots. Sequence analysis revealed conserved cis-acting elements (Box A and AC-II element) present in the Na4CL promoter. Additionally, a Na4CL RNAi construct was transformed into tobacco. Transgenic tobaccos displayed significant down-expression of endogenesis 4CL and reduced lignin contents. Conclusion: These results contribute to the knowledge of the presence of Na4CL gene and its possible role in phenylpropanoid metabolism.

The exploration of the antibacterial mechanism of fe3+ against bacteria

This study demonstrated that the bacteria could adsorb Fe3+ and reduce Fe3+ to Fe2+. Iron had significant bacteriostatic effects, which were directly proportional to the iron concentration and under the influence of pH and chelator. It presumed that the inhibition of Fe3+ acts through the formation of hydroxyl free radicals.

The Exploration of the Antibacterial Mechanism of FE(3+) against Bacteria.

This study demonstrated that the bacteria could adsorb Fe(3+) and reduce Fe(3+) to Fe(2+). Iron had significant bacteriostatic effects, which were directly proportional to the iron concentration and under the influence of pH and chelator. It presumed that the inhibition of Fe(3+) acts through the formation of hydroxyl free radicals.

The exploration of the antibacterial mechanism of fe3+ against bacteria

This study demonstrated that the bacteria could adsorb Fe3+ and reduce Fe3+ to Fe2+. Iron had significant bacteriostatic effects, which were directly proportional to the iron concentration and under the influence of pH and chelator. It presumed that the inhibition of Fe3+ acts through the formation of hydroxyl free radicals.

Screening and enzymatic study of a composite microbial system FH3

Five strains of fungi and 18 strains of bacteria were isolated from the soil and horse manure with cellulose as the sole carbon source. Among them, two fungal, F9 and F13, and two bacterial, B16 and B21, showed the highest filter paper activities, which were 7.79 U g-1, 9.84 U g-1, 7.34 U g-1 and 9.68 U g-1, respectively. Four microbial systems, designed as FH1 (F13+B21), FH2 (F13+B16+B21), FH3 (F9+B16+B21) and FH4 (F13+F9+B16+B21) were developed. The fermentation studies showed that the filter paper activity of the composite microbial system FH3 was higher than the others, which was 21.34 U g-1. The medium with bran and filter paper as the carbon source and peptone as nitrogen source was optimal and the maximum cellulase activity was reached at 30~35ºC and pH 6.0~6.5 when FH3 was incubated for 48 h. The enzymatic reaction conditions were estimated at 45~55 ºC, pH 4.5~5.5 and the thermal stability temperature was up to 60 ºC.