Characterization of Violacein Producing Host Pseudoduganella sp. NI28 and Production of Deoxyviolacein with Recombinant Escherichia coli Strain

Department of Biological SciencesViolacein is bacteria pigment made several strain such as J.lividum, C.violaceum, Duganella sp., Pseudoduganella sp., Collimonas sp. which found various environment from glacial to subtropical climate. The usage of violacein in the bio-application in the field is diverse to block growth of several type of living organism: gram positive bacteria, fungus, virus, protozoa, nematodes, parasites and some cancer cell line like Hep2, KM12, MOLT-4. Because of this versatile application potent, needs of amount of violacein and its derivation will be increase near future. Nevertheless this positive application prediction, the production of violacein and its derivation is just beginning stage. The crude violacein contained violacein and its derivation specific productivity is reported 12.4mg/L?h and its final concentration is 0.44g/L using C.violaceum natural violacein producing host. In recombinant strain violacein producing field, recent reported recombinant E. coli produce pure violacein 0.710g/L, however, specific productivity is 3.1mg/ L?h. On the other hands violacein measurement method is not standardized, spectrophotometry is generally used for measurement violacein but extinction coefficient doesn???t have unity every study. Moreover purity of crude violacein is also questionable without HPLC analysis. Thus violacein production field need more study for enhance productivity and standardizing measurement of crude violacein. Characterization of violacein producing strain Pseudoduganella sp. NI28 found forest soil sample. P. sp. NI28 is similar to Psedoduganella violanceinigra YIM 31327 98.8% for 16s rRNA, 95.9% for gyrB, 88.8% for vioA. Even this similarity NI28 shown better crude violacein production tendency in NB media two Pseudoduganella strains shown significantly different production of crude violacein, NI28 produced 14mg/L but type strain produced under 0.1mg at 24 hours culture. Following HPLC analysis, NI28 crude violacein contain more than 95% violacein in the extracted violacein almost similar purity of commercial violacein (Sigma Aldrich. USA). Antibacterial effect of extracted violacein from NI28 shown 78%, 96% and 99.5% S. aureus population decrease in violacein concentration 15??M, 30??M and 60??M. Co-culture of violacein producing strain with S. aureus was tested with NI28 and type strain in the NB media using violacein productivity difference, violacein producing is more helpful to compete co-culture condition to eliminate viability of S. aureus in the media. For enhance of production of violacein, E. coli GPT vio and E. coli GPT pCOM10vio transformed tryptophan over-producing E. coli was produced crude violacein in 37??C fermentation. GPT vio produce more 95% concentration of deoxyviolacein form HPLC analysis. The final concentration of deoxyviolacein form GPT vio is 584.8mg/L, specific productivity of 24 hours fermentation is 20.91mg/L?h which was 1.65 fold high specific productivity compare than recent reported strain of deoxyviolacein productivity.ope

Combined Application of Bacterial Predation and Violacein to Kill Polymicrobial Pathogenic Communities

Violacein is a bisindole antibiotic that is effective against Gram-positive bacteria while the bacterial predator, Bdellovibrio bacteriovorus HD100, predates on Gram-negative strains. In this study, we evaluated the use of both together against multidrug resistant pathogens. The two antibacterial agents did not antagonize the activity of the other. For example, treatment of Staphylococcus aureus with violacein reduced its viability by more than 2,000-fold with or without B. bacteriovorus addition. Likewise, predation of Acinetobacter baumannii reduced the viability of this pathogen by more than 13,000-fold, regardless if violacein was present or not. When used individually against mixed bacterial cultures containing both Gram-positive and Gram-negative strains, violacein and B. bacteriovorus HD100 were effective against only their respective strains. The combined application of both violacein and B. bacteriovorus HD100, however, reduced the total pathogen numbers by as much as 84,500-fold. Their combined effectiveness was also demonstrated using a 4-species culture containing S. aureus, A. baumannii, Bacillus cereus and Klebsiella pneumoniae. When used alone, violacein and bacterial predation reduced the total population by only 19% and 68%, respectively. In conjunction with each other, the pathogen viability was reduced by 2,965-fold (99.98%), illustrating the prospective use of these two antimicrobials together against mixed species populations

Solid tumors of the pancreas can put on a mask through cystic change

<p>Abstract</p> <p>Background</p> <p>Solid pancreatic tumors such as pancreatic ductal adenocarcinoma (PDAC), solid pseudopapillary tumor (SPT), and pancreatic endocrine tumor (PET) may occasionally manifest as cystic lesions. In this study, we have put together our accumulated experience with cystic manifestations of various solid tumors of the pancreas.</p> <p>Methods</p> <p>From 2000 to 2006, 376 patients with pancreatic solid tumor resections were reviewed. Ten (2.66%) of these tumors appeared on radiological imaging studies as cystic lesions. We performed a retrospective review of medical records and pathologic findings of these 10 cases.</p> <p>Results</p> <p>Of the ten cases in which solid tumors of the pancreas manifested as cystic lesions, six were PDAC with cystic degeneration, two were SPT undergone complete cystic change, one was cystic PET, and one was a cystic schwannoma. The mean tumor size of the cystic portion in PDAC was 7.3 cm, and three patients were diagnosed as 'pseudocyst' with or without cancer. Two SPT were found incidentally in young women and were diagnosed as other cystic neoplasms. One cystic endocrine tumor was preoperatively suspected as intraductal papillary mucinous neoplasm or mucinous cystic neoplasm.</p> <p>Conclusions</p> <p>Cystic changes of pancreas solid tumors are extremely rare. However, the possibility of cystic manifestation of pancreas solid tumors should be kept in mind.</p

Violacein: Properties and Production of a Versatile Bacterial Pigment

Violacein-producing bacteria, with their striking purple hues, have undoubtedly piqued the curiosity of scientists since their first discovery. The bisindole violacein is formed by the condensation of two tryptophan molecules through the action of five proteins. The genes required for its production, vio ABCDE, and the regulatory mechanisms employed have been studied within a small number of violacein-producing strains. As a compound, violacein is known to have diverse biological activities, including being an anticancer agent and being an antibiotic against Staphylococcus aureus and other Gram-positive pathogens. Identifying the biological roles of this pigmented molecule is of particular interest, and understanding violacein&apos;s function and mechanism of action has relevance to those unmasking any of its commercial or therapeutic benefits. Unfortunately, the production of violacein and its related derivatives is not easy and so various groups are also seeking to improve the fermentative yields of violacein through genetic engineering and synthetic biology. This review discusses the recent trends in the research and production of violacein by both natural and genetically modified bacterial strains.open0

Use of Resazurin To Rapidly Enumerate Bdellovibrio and Like Organisms and Evaluate Their Activities

A method to rapidly quantify predatory bacterial cell populations using resazurin reduction to resorufin and its resulting fluorescence kinetics (dF/dt) are described. The reliability of this method to measure the predatory populations was demonstrated with the type strain, Bdellovibrio bacteriovorus HD100, as well as B. bacteriovorus 109J and two natural isolates, Halobacteriovorax strains JA-1 and JA-3, with clear correlation when densities were between 107 and 109 PFU/ml. Resazurin was also used to evaluate how B. bacteriovorus HD100 and Halobacteriovorax strain JA-1 respond to harmful conditions, i.e., exposure to sodium dodecyl sulfate (SDS), with both the dF/dt and PFU/ml indicating Halobacteriovorax strain JA-1 is more sensitive to this surfactant. Tests were also performed using media of different osmolalities, with the dF/dt values matching the 24-h predatory activities reasonably well. Finally, this method was successfully applied in near real-time analyses of predator-prey dynamics and, when coupled with SDS, was capable of differentiating between the predatory and prey populations. All of these tests serve to prove this method is (i) very rapid, needing only 15 min from start to finish; (ii) very reliable with different predatory bacterial species; and (iii) very versatile as it can be easily adapted to measure predatory numbers and activities in a range of experiments

Biotechnological Activities and Applications of Bacterial Pigments Violacein and Prodigiosin

In this review, we discuss violacein and prodigiosin, two chromogenic bacterial secondary metabolites that have diverse biological activities. Although both compounds were &quot;discovered&quot; more than seven decades ago, interest into their biological applications has grown in the last two decades, particularly driven by their antimicrobial and anticancer properties. These topics will be discussed in the first half of this review. The latter half delves into the current efforts of groups to produce these two compounds. This includes in both their native bacterial hosts and heterogeneously in other bacterial hosts, including discussing some of the caveats related to the yields reported in the literature, and some of the synthetic biology techniques employed in this pursuit

Advances in Neuroprotective Ingredients of Medicinal Herbs by Using Cellular and Animal Models of Parkinson’s Disease

Parkinson’s disease (PD) is a multifactorial disorder, which is neuropathologically identified by age-dependent neurodegeneration of dopaminergic neurons in the substantia nigra. Development of symptomatic treatments has been partly successful for PD research, but there remain a number of inadequacies in therapeutic strategies for the disease. The pathogenesis of PD remains intricate, and the present anti-PD treatments appears to be clinically insufficient. Comprehensive research on discovery of novel drug candidates has demonstrated that natural products, such as medicinal herbs, plant extracts, and their secondary metabolites, have great potential as therapeutics with neuroprotective activity in PD. Recent preclinical studies suggest that a number of herbal medicines and their bioactive ingredients can be developed into optimum pharmaceuticals for treating PD. In many countries, traditional herbal medicines are used to prevent or treat neurodegenerative disorders, and some have been developed as nutraceuticals or functional foods. Here we focus on recent advances of the evidence-linked neuroprotective activity of bioactive ingredients of herbal origin in cellular and animal models of PD research

Consumption of Oleic Acid During Matriphagy in Free-Living Nematodes Alleviates the Toxic Effects of the Bacterial Metabolite Violacein

Maternal behaviors benefit the survival of young, contributing directly to the mother&apos;s reproductive fitness. An extreme form of this is seen in matriphagy, when a mother performs the ultimate sacrifice and offers her body as a meal for her young. Whether matriphagy offers only a single energy-rich meal or another possible benefit to the young is unknown. Here, we characterized the toxicity of a bacterial secondary metabolite, namely, violacein, in Caenorhabditis elegans and found it is not only toxic towards adults, but also arrests growth and development of C. elegans larvae. To counteract this, C. elegans resorted to matriphagy, with the mothers holding their eggs within their bodies and hatching the young larvae internally, which eventually led to the mothers&apos; death. This violacein-induced matriphagy alleviated some of the toxic effects of violacein, allowing a portion of the internally-hatched young to bypass developmental arrest. Using genetic and pharmacological experiments, we found the consumption of oleate, a monounsaturated fatty acid produced by the mother, during matriphagy is partially responsible. As such, our study provides experimental evidence of why such a drastic and peculiar maternal behavior may have arisen in nematode natural habitats

Preclinical evaluation of injectable sirolimus formulated with polymeric nanoparticle for cancer therapy

Nanoparticles are useful delivery vehicles for promising drug candidates that face obstacles for clinical applicability. Sirolimus, an inhibitor of mammalian target of rapamycin has gained attention for targeted anticancer therapy, but its clinical application has been limited by its poor solubility. This study was designed to enhance the feasibility of sirolimus for human cancer treatment. Polymeric nanoparticle (PNP)–sirolimus was developed as an injectable formulation and has been characterized by transmission electron microscopy and dynamic light scattering. Pharmacokinetic analysis revealed that PNP–sirolimus has prolonged circulation in the blood. In addition, PNP–sirolimus preserved the in vitro killing effect of free sirolimus against cancer cells, and intravenous administration displayed its potent in vivo anticancer efficacy in xenograft tumor mice. In addition, PNP–sirolimus enhanced the radiotherapeutic efficacy of sirolimus both in vitro and in vivo. Clinical application of PNP–sirolimus is a promising strategy for human cancer treatment