Degradation Of Vanillic Acid Research Articles

Autotoxic effects of applied vanillic acid on Dynamic succession of soil microbial community

We studied the degradation of vanillic acid in soil was studied by high performance liquid chromatography and gas chromatography. Illumina MISEQ high-throughput sequencing was used to identify the abundance of bacteria and fungi in soil. The results showed that when the concentration of vanillic acid decreased to a certain level in the soil, its degradation rate became slow. The application of vanillic acid gradually decreased the total number of bacterial OTUs in soil, while the total number of fungal OTUs increased. At the same time, the richness and diversity of bacteria were always higher than fungi. Key microbial taxa at different degradation stages of vanillic acid were identified at the phylum and genus level, including bacteria (<i>Proteobacteria, Firmicutes, Actinobacteria, Chloroflexi, Methylibium, Methylobacillus, Aeromicrobium, Pseudonocardia</i>) and Fungi (<i>Ascomycota, Zygomycota, Basidiomycota, Rhodotorula, Mortierella

Nanoparticle effect on degradation of vanillic acid, a germination inhibiting dormancy factor present in Cyperus rotundus

Cyperus rotundus is one of the most invasive perennial sedge weed considered as the world's worst weed. The tubers of the weed remain viable for more than three years and pass over the harsh weather period by preventing the germination of buds present in the tubers. Due to dormancy, the tubers may sustain in the soil for longer and interfere with the crops raised in the following season. Phenols are considered as the major factor of dormancy in Cyperus rotundus tubers. Among different phenolic acids, vanillic acid is dominated, found under long and continuous stress. Nanoparticles are capable to degrade the phenols. In order to confirm whether the nanoparticles have effect on degradation of phenol present in Cyperus rotundus, the dominant phenol present in the tuber i.e., vanillic acid was chosen. Experiment was conducted at the department of Nano Science and Technology, Tamil Nadu Agricultural University, Coimbatore to find the effect of different nanoparticles such as iron oxide, silver, titanium dioxide and zinc oxide on commercially available vanillic acid degradation during 2013–15. The maximum degradation of vanillic acid was observed with iron oxide nanoparticles at 25 mg i.e., 60.6% degradation compared to control. Titanium dioxide, zinc oxide and silver nanoparticles at 25 mg recorded the 54.5, 49.3 and 24.8% degradation, respectively The purple nutsedge (Cyperus rotundus) causes serious problems in many crops all over the world than any other weed (Kadir et al. 2000). Often forms dense colonies and greatly reduces the crop yields. The sedge weed propagates mainly by producing a complex underground system of rhizomes, basal bulbs and tubers (Stoller 1975). The tubers remain viable for more than three years and pass over the harsh weather period by preventing the germination of buds present in the tubers. Jangaard et al (1971) reported that increasing phenolic compounds and abscissic acids in the tubers reduced the sprouting. C. rotundus tubers contain vanillic, coumaric, ferulic, hydroxybenzoic and protochatechuic acids (Komai et al. 1991). Among these, vanillic acid is dominant. Due to its highest free radical scavenging potential, vanillic acid is expected to protect plant roots from the adverse effects produced by free radicals (Swigonska et al. 2014). Due to dormancy, the tubers may sustain in the soil for longer time and interfere with the crops raised in the following season. Under this situation, new strategies have to be designed to break the dormancy of the tubers.

Expression and characterization of novel laccase gene from Pandoraea sp. ISTKB and its application

In the present study, a non-blue laccase gene from previously reported lignin degrading bacterium, Pandoraea sp. ISTKB, was isolated, cloned and expressed in E. coli. Bioinformatics analysis of sequence discovered twin-arginine translocation signal sequence, copper binding motifs and presence of more random coil compare to helices and sheets in structure. The enzyme was found to be active on wide pH range and the pH optima was observed at pH 4 and 8 on substrate 2,2′-Azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) and 2,6-Dimethoxyphenol respectively. This is a thermophilic enzyme with maximum activity around 50–70 °C. The enzyme was further characterized by spectroscopy, reaction kinetics and effect of metal ions and inhibitors were studied. Compared to laccase alone; the treatment of dyes with laccase plus mediator resulted in enhanced decolorization of crystal violet, methylene blue, azure B, carmine and Congo red but the effect of mediator was not observed on trypan blue. Laccase treatment triggered polymerization on vanillic acid (VA) and kraft lignin (KL). Laccase plus mediator treatment reversed the polymerization and resulted in transformation or degradation of VA and KL. This thermophilic and alkalophilic non-blue laccase from Pandoraea sp. ISTKB is promising with prospective biotechnological application.

Development of an Improved System for the Generation of Knockout Mutants of Amycolatopsis sp. Strain ATCC 39116.

The Gram-positive actinomycete Amycolatopsis sp. strain ATCC 39116 is used for the industrial production of natural vanillin. Previously, the only gene deletion performed in this strain targeted the gene vdh, coding for a vanillin dehydrogenase. The generation of this mutant suffered from a high number of illegitimate recombinations and a low rate of homologous recombination. To alleviate this, we constructed an optimized deletion system based on a modified suicide vector. Thereby, we were able to increase the rate of homologous integration from less than 1% of the analyzed clones to 20% or 50%, depending on the targeted gene. We were furthermore able to reduce the screening effort needed to identify homogenotes through the use of the rpsL gene from Saccharopolyspora erythraea, which confers streptomycin sensitivity on clones still carrying the suicide vector. The new suicide vector is p6SUI5ERPSL, and its applicability was demonstrated by the deletion of three Amycolatopsis gene clusters. The deletion of the first of the gene clusters, coding for an aldehyde oxidase (yagRST), led to no altered phenotype compared to the parent strain; deletion of the second, coding for a vanillic acid decarboxylase (vdcBCD), led to a phenotype that was strongly impaired in its growth with vanillic acid as the sole carbon source and also unable to form guaiacol; and deletion of the third, coding for a vanillate demethylase (vanAB), led to only a negligible impact in comparison. Therefore, we showed that decarboxylation of vanillic acid is the main degradation pathway in Amycolatopsis sp. ATCC 39116 while the demethylation plays only a minor role and does not compensate the deletion of vdcBCD IMPORTANCE: Amycolatopsis sp. ATCC 39116 is an important microorganism used for the production of natural vanillin from ferulic acid. In contrast to this importance, it has previously been shown that this strain is hard to manipulate on a genetic level. We therefore generated an optimized system to facilitate the deletion of genes in this strain. This allowed us to greatly reduce the time and work requirements for generating deletions. This could allow the improvement of vanillin production in the future and also the elucidation of metabolic pathways. To test our deletion system, we deleted three gene clusters in Amycolatopsis sp. ATCC 39116. One showed no involvement in the metabolism of vanillin, while the second proved to be the main pathway of vanillic acid degradation and completely stopped the formation of the off-flavor guaiacol. The third appeared to have only a negligible impact on the degradation of vanillic acid.