Actinoplanes capillaceus sp. nov., a new species of the genus Actinoplanes

Two motile actinomycete strains, K95–5561^T and K95–5562, were isolated from a soil sample collected at Sayama City, Saitama Prefecture, Japan. They produced bell shaped spore vesicles (sporangia) with hairy surfaces on substrate hyphae. When released into water, the sporangiospores became motile by a tuft of polar flagella. The chemotaxonomic and morphological characteristics together with 16S rRNA gene sequence data indicated that the two isolates belonged to the genus Actinoplanes. The two strains were assigned to a single species on the basis of phenotypic, notably cultural, morphological and physiological characteristics, and DNA-DNA pairing data. The two strains were distinguished from representatives of all validly described species of Actinoplanes using a combination of genotypic and phenotypic properties. It is, therefore, proposed that strains K95–5561 and K95–5562 be recognized as a new species of the genus Actinoplanes with the name Actinoplanes capillaceus sp. nov. The type strain of the species is strain K95–5561^T (=JCM 10268^T =IFO 16408^T). The invalidly proposed species `Ampullariella cylindrica', `Ampullariella pekinensis' and `Ampullariella pilifera' were assigned to Actinoplanes capillaceus on the basis of genotypic and phenotypic data.     

Cloning and characterization of a ribonuclease L inhibitor from the silkworm, Bombyx mori.

The ribonuclease L (RNase L) pathway plays an important role in the response of cells to double-stranded RNA (dsRNA) during the events such as virus infection. Ribonuclease L inhibitor (RLI) belonging to the ABC transporter family is known as a regulator of the RNase L pathway. The homologs of RLI were reported in many organisms including the fruit fly and mosquito, but their functions in insects and arthropods have not been elucidated to date. In the present study, we cloned a cDNA of a silkworm RLI homolog, termed BmRLI, and its nucleotide sequence was determined. RT-PCR analysis revealed that the expression of BmRLI mRNA was marked in the testis, ovary and fat body. From the cDNA, recombinant protein with an apparent molecular mass of 69 kDa was expressed in Escherichia coli and cultured insect cells. Although no obvious effect of up-regulation of the BmRLI expression on RNAi was observed, its down-regulation slightly reduced RNAi efficiency.     

Design and synthesis of cell-permeable fluorescent nitrilotriacetic acid derivatives

Fluorescence labeling of the target molecules using a small molecule-based probe is superior than a method using genetically expressed green fluorescence protein (GFP) in terms of convenience in its preparation and functionalization. Fluorophore-nitrilotriacetic acid (NTA) conjugates with several ester protecting groups were synthesized and evaluated for their cell membrane permeability by fluorescence microscopy analysis. One of the derivatives, acetoxymethyl (AM)-protected NTA conjugate is hydrolyzed, resulting in intracellular accumulation, thus providing localized fluorescence intensity in cells. This modification is expected as an effective method for converting a non-cell membrane permeable NTA-BODIPY conjugates to a cell membrane permeable derivatives.     

A comparative study of the biomass properties of Erianthus and sugarcane: lignocellulose structure,alkaline delignification rate,and enzymatic saccharification efficiency

A comprehensive understanding of the structure and properties of gramineous lignocelluloses is needed to facilitate their uses in biorefinery. In this study, lignocelluloses from fractionated internode tissues of two taxonomically close species, Erianthus arundinaceus and sugarcane (Saccharum spp.), were characterized. Our analyses determined that syringyl (S) lignins were predominant over guaiacyl (G) or p-hydroxyphenyl (H) lignins in sugarcane tissues; on the other hand, S lignin levels were similar to those of G lignin in Erianthus tissues. In addition, tricin units were detected in sugarcane tissues, but not in Erianthus tissues. Distributions of lignin inter-monomeric linkage types were also different in Erianthus and sugarcane tissues. Alkaline treatment removed lignins from sugarcane tissues more efficiently than Erianthus tissues, resulting in a higher enzymatic digestibility of sugarcane tissues compared with Erianthus tissues. Our data indicate that Erianthus biomass displayed resistance to alkaline delignification and enzymatic digestion.     

Decision tree classification of behaviors in the nesting process of green turtles (Chelonia mydas) from tri-axial acceleration data

Sea turtles are endangered marine-adapted reptiles that are obligate terrestrial nesters. They have a nesting process that involves a series of behavioral phases: (1) crawling, (2) digging a body pit, (3) digging an egg chamber, (4) depositing eggs, (5) covering the egg chamber, and (6) camouflaging the site. Discrimination among these behavioral phases is necessary for estimating which parts of the nesting process are affected by human activities or characteristics of beaches. We calculated multivariate features from tri-axial accelerations obtained by a data logger to extract key features for discriminating between these behavioral phases of green turtles (Chelonia mydas). The developed decision tree classifier discriminated these behaviors with high accuracy, resulting in 5 behaviors after combining digging a body pit and camouflaging the site (86.207 %). The structure of the tree showed key features for discriminating the 5 behaviors on the basis of differences in the movements of turtles. The decision rules in this study will enable us to discriminate behavioral phases quantitatively without observer interference, thereby providing a basis for estimating turtle energy budget and the influence of human activities on nesting behavior.     

Regulation of Dual Glycolytic Pathways for Fructose Metabolism in Heterofermentative Lactobacillus panis PM1

Lactobacillus panis PM1 belongs to the group III heterofermentative lactobacilli that use the 6-phosphogluconate/phosphoketolase (6-PG/PK) pathway as their central metabolic pathway and are reportedly unable to grow on fructose as a sole carbon source. We isolated a variant PM1 strain capable of sporadic growth on fructose medium and observed its distinctive characteristics of fructose metabolism. The end product pattern was different from what is expected in typical group III lactobacilli using the 6-PG/PK pathway (i.e., more lactate, less acetate, and no mannitol). In addition, in silico analysis revealed the presence of genes encoding most of critical enzymes in the Embden-Meyerhof (EM) pathway. These observations indicated that fructose was metabolized via two pathways. Fructose metabolism in the PM1 strain was influenced by the activities of two enzymes, triosephosphate isomerase (TPI) and glucose 6-phosphate isomerase (PGI). A lack of TPI resulted in the intracellular accumulation of dihydroxyacetone phosphate (DHAP) in PM1, the toxicity of which caused early growth cessation during fructose fermentation. The activity of PGI was enhanced by the presence of glyceraldehyde 3-phosphate (GAP), which allowed additional fructose to enter into the 6-PG/PK pathway to avoid toxicity by DHAP. Exogenous TPI gene expression shifted fructose metabolism from heterolactic to homolactic fermentation, indicating that TPI enabled the PM1 strain to mainly use the EM pathway for fructose fermentation. These findings clearly demonstrate that the balance in the accumulation of GAP and DHAP determines the fate of fructose metabolism and the activity of TPI plays a critical role during fructose fermentation via the EM pathway in L. panis PM1.     

Isolation and characterization of novel 1,3-propanediol-producing Lactobacillus panis PM1 from bioethanol thin stillage

Conversion of glycerol to 1,3-propanediol (1,3-PDO) is an attractive option to increase the economic efficiency of the biofuel industry. A bacterial strain that produced 1,3-PDO in the presence of glycerol was isolated from thin stillage, the fermentation residue of bioethanol production. This 1,3-PDO-producing organism was identified as Lactobacillus panis through biochemical characteristics and by 16S rRNA sequencing. Characterization of the L. panis strain hereafter designated as PM1 revealed it was an aerotolerant acidophilic anaerobe able to grow over a wide range of temperatures; tolerant to high concentrations of sodium chloride, ethanol, acetic acid, and lactic acid; and resistant to many common antibiotics. L. panis PM1 could utilize glucose, lactose, galactose, maltose, xylose, and arabinose, but could not grow on sucrose or fructose. Production of 1,3-PDO by L. panis PM1 occurred only when glucose was available as the carbon source in the absence of oxygen. These metabolic characteristics strongly suggested NADH recycling for glucose metabolism is achieved through 1,3-PDO production by this strain. These characteristics classified L. panis PM1 within the group III heterofermentative lactic acid bacteria, which includes the well-characterized 1,3-PDO-producing strain, Lactobacillus reuteri. Metabolite production profiles showed that L. panis PM1 produced considerable amounts of succinic acid (~11–12 mM) from normal MRS medium, which distinguishes this strain from L. reuteri strains.     

Continuous Hydrolysis of Soluble Starch by Free β-Amylase and Pullulanase Using an Ultrafiltration Membrane Reactor

Enzyme hydrolysis of soluble starch by free β-amylase and pullulanase for the production of maltose was done by the simultaneous use of a stirred tank reactor and an ultrafiltration membrane. Higher conversions of starch to maltose were obtained in the permeates than that in a batch reaction. Using the basic mass balance and rate equations, concentrations of maltose, maltotriose, and substrate in the retentates and permeates could be simulated effectively. More than 99.9% of enzyme was found to be rejected by the membrane. The obtained volumetric productivities were several times higher than those reported in other systems. This system was found to have high maltose productivity with a short mean residence time, being easily controlled by transmembrane pressure.     

Metronomic Chemotherapy: Possible Clinical Application in Advanced Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular highly angiogenic tumor usually associated with liver cirrhosis. Vascular endothelial growth factor plays a critical role in vascular development in HCC. In contrast to the treatment of early-stage HCC, the treatment options for advanced HCC are limited and prognosis is often poor, which contributes to this tumor type being the third leading cause of cancer-related deaths worldwide. Metronomic chemotherapy, which was originally designed to inhibit angiogenesis, involves low-dose chemotherapeutic agents administered in a frequent regular schedule with no prolonged breaks and minimizes severe toxicities. We reviewed the potential effects and impact of metronomic chemotherapy in preclinical studies with HCC models and in patients with advanced HCC, especially when combined with a molecular targeted agent. Metronomic chemotherapy involves multiple mechanisms that include antiangiogenesis and antivasculogenesis, immune stimulation by reducing regulatory T cells and inducing dendritic cell maturation, and possibly some direct tumor cell targeting effects, including the cancer stem cell subpopulation. The total number of preclinical studies with HCC models shows impressive results using metronomic chemotherapy-based protocols, especially in conjunction with molecular targeted agents. Four clinical trials and two case reports evaluating metronomic chemotherapy for HCC indicate it to be a safe and potentially useful treatment for HCC. Several preclinical and clinical HCC studies suggest that metronomic chemotherapy may become an alternative type of chemotherapy for advanced unresectable HCC and postsurgical adjuvant treatment of HCC.