Efficient production of lactic acid from sucrose and corncob hydrolysate by a newly isolated <Emphasis Type="Italic">Rhizopus oryzae</Emphasis> GY18

The aim of this study is to investigate production of l-lactic acid from sucrose and corncob hydrolysate by the newly isolated R. oryzae GY18. R. oryzae GY18 was capable of utilizing sucrose as a sole source, producing 97.5 g l⁻¹ l-lactic acid from 120 g l⁻¹ sucrose. In addition, the strain was also efficiently able to utilize glucose and/or xylose to produce high yields of l-lactic acid. It was capable of producing up to 115 and 54.2 g l⁻¹ lactic acid with yields of up to 0.81 g g⁻¹ glucose and 0.90 g g⁻¹ xylose, respectively. Corncob hydrolysates obtained by dilute acid hydrolysis and enzymatic hydrolysis of the cellulose-enriched residue were used for lactic acid production by R. oryzae GY18. A yield of 355 g lactic acid per kg corncobs was obtained after 72 h incubation. Therefore, sucrose and corncobs could serve as potential sources of raw materials for efficient production of lactic acid by R. oryzae GY18.     

Headwater streams and forest management: Does ecoregional context influence logging effects on benthic communities?

Effects of forest management on stream communities have been widely documented, but the role that climate plays in the disturbance outcomes is not understood. In order to determine whether the effect of disturbance from forest management on headwater stream communities varies by climate, we evaluated benthic macroinvertebrate communities in 24 headwater streams that differed in forest management (logged-roaded vs. unlogged-unroaded, hereafter logged and unlogged) within two ecological sub-regions (wet versus dry) within the eastern Cascade Range, Washington, USA. In both ecoregions, total macroinvertebrate density was highest at logged sites (P = 0.001) with gathering-collectors and shredders dominating. Total taxonomic richness and diversity did not differ between ecoregions or forest management types. Shredder densities were positively correlated with total deciduous and Sitka alder (Alnus sinuata) riparian cover. Further, differences in shredder density between logged and unlogged sites were greater in the wet ecoregion (logging × ecoregion interaction; P = 0.006) suggesting that differences in post-logging forest succession between ecoregions were responsible for differences in shredder abundance. Headwater stream benthic community structure was influenced by logging and regional differences in climate. Future development of ecoregional classification models at the subbasin scale, and use of functional metrics in addition to structural metrics, may allow for more accurate assessments of anthropogenic disturbances in mountainous regions where mosaics of localized differences in climate are common.     

Co-administration of Monosialoganglioside and Skeletal Muscle Cells on Dorsal Root Ganglion Neuronal Phenotypes In Vitro

The neuropeptide-immunoreactive (IR) and neurofilament-IR neurons are two major phenotypical classes in dorsal root ganglion (DRG). Targets of neuronal innervation play a vital role in regulating the survival and differentiation of innervating neurotrophin-responsive neurons. Monosialoganglioside (GM1) has been considered to have a neurotrophic factor-like activity. Both GM1 and target skeletal muscle (SKM) cells are essential for the maintenance of the function of neurons. However, whether target SKM cells and GM1, alone or associated, generate neuropeptide or neurofilament expression remains unclear. The aim of the present study is to investigate the effects of GM1 or/and SKM on DRG neuronal phenotypes. DRG neurons containing the neuropeptide substance P (SP) and neurofilament 200 (NF-200) were quantified using immunofluorescent labeling in cultures of DRG, which was dissected out at times before (at embryonic days 12.5, E12.5) and after (at E19.5) sensory neurons contact peripheral targets in vivo. DRG neurons were cultured in absence or presence of GM1 or/and SKM cells. In this experiment, we found that: (1) GM1 promoted expression of SP and NF-200 in E12.5 DRG cultures; (2) SKM cells promoted expression of NF-200 but not SP in E12.5 DRG cultures; (3) GM1 and target SKM cells had additive effects on expression of SP and NF-200 in E12.5 DRG cultures; and (4) SKM or/and GM1 did not have effects on expression of SP and NF-200 in E19.5 DRG cultures. These results suggested that GM1 could influence DRG, two major neuronal phenotypes, before sensory neurons contact peripheral targets in vivo. Target SKM cells could only influence neurofilament-expressed neuronal phenotype before sensory neurons contact peripheral targets in vivo. GM1 and SKM cells had the additive effects on two major DRG neuronal classes, which express neuropeptide or neurofilament when DRG cells were harvested before sensory neurons contact peripheral targets in vivo. These results offered new clues for a better understanding of the association of GM1 or/and SKM with neuronal phenotypes.     

A Novel NAD<Superscript>+</Superscript>-dependent aldehyde dehydrogenase encoded by the <Emphasis Type="Italic">puuC</Emphasis> gene of <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> DSM 2026 that utilizes 3-hydroxypropionaldehyde as a substrate

3-Hydroxypropionic acid (3-HP), a versatile and valuable platform chemical, has diverse industrial applications; but its biological production from glycerol is often limited by the capability of the enzyme aldehyde dehydrogenase (ALDH) to convert an intermediary compound, 3-hydroxypropionaldehyde (3-HPA), to 3-HP. In this study, we report a new ALDH, PuuC, from Klebsiella pneumoniae DSM 2026, that efficiently converts 3-HPA to 3-HP. The identified gene puuC was cloned, expressed in Escherichia coli, purified, and characterized for its properties. The recombinant enzyme with a molecular weight of 53.8 kDa exhibited broad substrate specificity for various aliphatic aldehydes, especially C₂–C₅ aldehydes. NAD⁺ was the preferred coenzyme for the oxidation of most aliphatic and aromatic aldehydes tested. The optimum pH and temperature for PuuC activity were pH 8.0 and 45°C. The K _m values for 3-HPA and NAD⁺ were 0.48 and 0.09 mM, respectively. The activity of PuuC was enhanced in the presence of reducing agents such as 2-mercaptoethanol or dithiothreitol, while several metal ions, particularly Hg²⁺, Ag⁺, and Cu²⁺ inhibited its activity. The predicted structure of PuuC indicated the presence of K191 and E194 in close proximity to the glycine motif, suggesting that PuuC belongs to class 2 ALDHs.     

Ocular Proteomics with Emphasis on Two-Dimensional Gel Electrophoresis and Mass Spectrometry

The intention of this review is to provide an overview of current methodologies employed in the rapidly developing field of ocular proteomics with emphasis on sample preparation, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry (MS). Appropriate sample preparation for the diverse range of cells and tissues of the eye is essential to ensure reliable results. Current methods of protein staining for 2D-PAGE, protein labelling for two-dimensional difference gel electrophoresis, gel-based expression analysis and protein identification by MS are summarised. The uses of gel-free MS-based strategies (MuDPIT, iTRAQ, ICAT and SILAC) are also discussed. Proteomic technologies promise to shed new light onto ocular disease processes that could lead to the discovery of strong novel biomarkers and therapeutic targets useful in many ophthalmic conditions.     

Relative contribution of agroforestry,rainforest and openland to local and regional bee diversity

Due to increasing human modification of tropical landscapes, the relative importance of natural habitats and agricultural systems has become a major conservation topic to counteract global species loss. We investigated the contribution of tropical primary forest, cacao agroforestry systems of varying management practices and openland to the temporal and spatial variation of diversity of native bee communities in the herb layer (Apidae, Hymenoptera) in Sulawesi (Indonesia). Local bee density and diversity were highest in openland, followed by agroforestry systems and were lowest in primary forests, revealing the importance of herbaceous food resources in the understorey. In contrast, highest regional bee richness was found in agroforestry systems, because of high community dissimilarity. Multidimensional scaling supported these findings with openland habitats showing more compactly clustered bee species communities than agroforestry habitats. In conclusion, the herb associated bee community profited from the opening of the landscape as a result of agricultural activities, while agroforestry systems increased bee species richness especially on a regional scale due to high management diversity.     

Understanding osmotic stress tolerance in leaves and nodules of two <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis> cultivars with contrasting drought tolerance

Drought and salinity are environmental constraints that affect crop yields worldwide. In nature, both stresses are multifaceted problems that are usually associated with other adverse circumstances which limit plant performance such as water shortage and nutrient deficits. In order to assess common features of both stresses, the effects of mannitol-induced osmotic stress were monitored using two Phaseolus vulgaris cultivars, Cv. ‘Flamingo’ (tolerant) and Cv. ‘Coco Blanc’ (sensitive) which differed in their drought and salinity tolerance. Growth, water relations, organic and inorganic compound accumulation and soluble protein contents were measured in leaves and nodules of these N₂-fixing plants. The aim of the present study was to check whether osmotic stress tolerance is associated with accumulation of some of these compounds either in leaves, nodules or both organs. At the whole-plant level, Cv. ‘Flamingo’ showed a better maintenance of plant biomass and shoot water status. At the cell level, this was related to a better osmotic adjustment ability both in leaves and nodules and also to a better adjustment of the cell wall elasticity. At the metabolic level, the contrasting accumulation of the different amino acids in nodules of each cultivar suggested that amino acids pathways can be regulated to different degrees under stress conditions. At the metabolic level, it seems that symbiosis in the sink organ (the nodule) plays a crucial role in conferring drought and salinity tolerance in the common bean.     

Somatic embryogenesis in mature zygotic embryos of <Emphasis Type="Italic">Picea likiangensis</Emphasis>

Somatic embryogenesis (SE) was successfully induced from mature zygotic embryos of seven families of Picea likiangensis (Franch.) Pritz after 20 weeks culture on initiation medium. Three basal media (one-half strength LM medium, one-half strength LP medium and improved LP medium) with different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzyladenine (6-BA) were tested but only one-half strength LM medium supplemented with 2,4-D and 6-BA was successful for the embryogenic cultures (EC) initiation. The initiation frequencies of EC varied greatly from different families when culturing on the same initiation medium. The highest frequency (41.3%) was induced from one of the families on one-half strength LM medium supplemented with 3 mg L⁻¹ 2,4-D and 1.5 mg L⁻¹ 6-BA and 16.83% on average for seven families. EC were subcultured and proliferated on the same medium as the initiation one every 10 days. 3 lines of EC induced from the same family were applied in maturation experiment. Cotyledonary somatic embryos were observed after EC were transferred to maturation media of one-half strength LM medium containing 20-80 mg L⁻¹ abscisic acid and 7.5% polyethylene glycol (PEG-4000). However, one-half strength LM medium supplemented with 40 mg L⁻¹ or 60 mg L⁻¹ ABA and 7.5% PEG gave the best maturation and the 3 lines showed different ability in maturation. Over 80% cotyledonary somatic embryos germinated normally on DCR medium containing 0.2% activated carbon. The success on SE induction of the species has provided an effective clonal propagation method for this important tree’s genetic improvement.     

Antiproliferative effect of D-glucuronyl C5-epimerase in human breast cancer cells

Background  

D-glucuronyl C5-epimerase (GLCE) is one of the key enzymes in the biosynthesis of heparansulfate proteoglycans. Down-regulation of GLCE expression in human breast tumours suggests a possible involvement of the gene in carcinogenesis. In this study, an effect of GLCE ectopic expression on cell proliferation and viability of breast carcinoma cells MCF7 in vitro and its potential molecular mechanisms were investigated.