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Effects of Trichosporon sp. in Combination with Calcium and Fungicide on Biocontrol of Postharvest Diseases in Apple Fruits

The capability of yeast Trichosporon sp., an antagonist isolated from peach fruit, in biological control was evaluated in apple ( Malus domestica Borkh. cv. Fuji) fruits, when inoculated with different concentrations of Botrytis cinerea Pers. and Penicillium expansum (Link) Thom, as well as in combination with calcium and fungicide. The concentrations of the yeast cells and pathogen spores obviously influenced disease incidence and lesion development in apples. There was a significant negative correlation between concentrations of the yeast cells and infectivity of the pathogens. When the yeast cell suspensions reached the concentration of 10 8 colony_forming units (CFU) /mL, there was no infection caused by B. cinerea and P. expansum with spore concentrations below 10 6 spores/mL in apple fruits. The yeast at concentrations of 10 6-10 7 CFU/mL in combination with fungicide (iprodione at 50 μL/L) provided control of decay caused by B. cinerea and P. expansum better than separate application. Effect of controlling gray mould and blue mould rots was enhanced when Trichosporon sp., even at low concentration of 10 5 CFU/mL, was applied in the presence of 1%-2% CaCl 2 in an aqueous suspension.

Marine Yeasts and Their Applications in Mariculture

The terrestrial yeasts have been receiving great attention in science and industry for over one hundred years because they can produce many kinds of bioactive substances. However, little is known about the bioactive substances of marine yeasts. In recent years, it has been found that marine yeasts have wide applications in mariculture and other fields. Therefore,marine yeasts, the bioactive substances from them and the applications of marine yeasts themselves and the bioactive substances they produced are reviewed in this paper.

Optimum Production and Characterization of an Acid Protease from Marine Yeast Metschnikowia reukaufii W6b

The marine yeast strain W6b isolated from sediment of the South China Sea was found to produce a cell-bound acid protease.The crude acid protease produced by this marine yeast showed the highest activity at pH 3.5 and 40 ℃.The optimal pH and temperature for the crude acid protease were in agreement with those for acid protease produced by the terrestrial yeasts.The optimal medium of the acid protease production was seawater containing 1.0% glucose, 1.5% casein, and 0.5% yeast extract, and the optimal cultivation conditions of the acid protease production were pH 4.0, a temperature of 25 ℃ and a shaking speed of 140 rmin-1.Under the optimal conditions, 72.5 UmL-1 of acid protease activity could be obtained in cell suspension within 48 h of fermentation at shake flask level.The acid protease production was induced by high-molecular-weight nitrogen sources and repressed by low-molecu-lar-weight nitrogen sources.Skimmed-milk-clotting test showed that the crude acid protease from the cell suspension of the yeast W6b had high skimmed milk coagulability.The acid protease produced by M.reukaufii W6b may have highly potential applications in cheese, food and fermentation industries.

Macrobenthic community structure and species composition in the Yellow Sea and East China Sea in jellyfi sh bloom

To understand the characteristics of macrobenthic structures and the relationship between environment and benthic assemblages in jellyfish bloom, we studied the macrobenthos and related environmental factors in the coastal waters of the Yellow Sea and East China Sea. Data were collected during two seasonal cruises in April and August of 2011, and analyzed with multivariate statistical methods. Up to 306 macrobenthic species were registered from the research areas, including 115 species of Polychaeta, 78 of Crustacea, 61 of Mollusca, 30 of Echinodermata, and 22 of other groups. Nine polychaete species occurred at frequencies higher than 25% from the sampling stations： Lumbrineris longifolia, Notomastus latericeus, Nin6e palmata, Ophelina acuminata, Nephtys oligobranchia, Onuphis geophiliformis, Glycera chirori, Terebellides stroemii, and Aricidea fragilis. Both the average biomass and abundance of macrobenthos are higher in August （23.8 g/m^2 and 237.7 ind./m^2） than those in April （11.3 g/m^2 and 128 ind./m^2）; the dissimilarity ofmacrobenthic structures among stations is as high as 70%. In terms of the dissimilarity values, we divided the stations into four clusters in spring and eight in summer. The ABC curve shows that the macrofauna communities in high jellyfish abundance were not changed. Canonical correspondence analysis showed that depth, temperature, median grain size, total organic carbon of sediment and total nitrogen in sediment were important factors affecting the macrozoobenthic community in the study area.

Alkaline Protease Production by a Strain of Marine Yeasts

Yeast strain 10 with high yield of protease was isolated from sediments of saltern near Qingdao, China. The protease had the highest activity at pH 9.0 and 45 ℃. The optimal medium for the maximum alkaline protease production of strain 10 was 2.5 g soluble starch and 2.0 g NaNO3 in 100 mL seawater with initial pH 6.0. The optimal cultivation conditions for the maximum protease production were temperature 24.5 ℃, aeration rate 8.0 L min -1 and agitation speed 150 r min -1. Under the optimal conditions, 623.1 U mg -1 protein of alkaline protease was reached in the culture within 30 h of fermentation.

A Carboxymethyl Cellulase from a Marine Yeast(Aureobasidium pullulans 98): Its Purification, Characterization, Gene Cloning and Carboxymethyl Cellulose Digestion

We have reported that A. pullulans 98 produces a high yield of cellulase. In this study, a carboxymethyl cellulase （CMCase） in the supematant of the culture ofA. pullulans 98 was purified to homogeneity, and the maximum production of CMCase was 4.51 U （mg protein）-1. The SDS-PAGE analysis showed that the molecular mass of the purified CMCase was 67.0kDa. The optimal temperature of the purified enzyme with considerable thermosensitivity was 40℃, much lower than that of the CMCases from other ftmgi. The optimal pH of the enzyme was 5.6, and the activity profile was stable in a range of acidity （pH 5,0-6.0）. The enzyme was activated by Na＋, Mg2＋, Ca2＋, K＋, Fe2＋ and Cu2＋, however, it was inhibited by Fe3＋, Ba2＋, Zn2＋, Mn2＋ and Ag＋. Km and Vmax values of the purified enzyme were 4.7mgmL-1 and 0.57 pmol L-1 min-1 （mg protein）-1, respectively. Only oligosaccharides with different sizes were released from carboxymethylcellulose （CMC） after hydrolysis with the purified CMCase. The putative gene encoding CMCase was cloned from A. pullulans 98, which contained an open reading flame of 954bp （EU978473）. The protein deduced contained the conserved domain of cellulase superfamily （glucosyl hydrolase family 5）. The N-terminal amino acid sequence of the purified CMCase was M-A-P-H-A-E-P-Q-S-Q-T-T-E-Q-T-S-S-G-Q-F, which was consistent with that deduced from the cloned gene. This suggested that the purified CMCase was indeed encoded by the cloned CMCase gene in this yeast.

Competitive adsorption of Cu(II) and Pb(II) ions from aqueous solutions by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae

To establish a theoretical foundation for simultaneous removal of multi-heavy metals,the adsorption of Cu（Ⅱ） and Pb（Ⅱ） ions from their single and binary systems by Ca-alginate immobilized activated carbon and Saccharomyces cerevisiae （CAS） was investigated.The CAS beads were characterized by Scanning electron microscope （SEM） and Fourier transformed infrared spectroscopy （FTTR）.The effect of initial pH,adsorbent dosage,contact time and initial metal ions concentration on the adsorption process was systematically investigated.The experimental maximum contents of Cu（Ⅱ） and Pb（Ⅱ） uptake capacity were determined as 64.90 and 166.31 mg/g,respectively.The pseudo-second-order rate equation and Langmuir isotherm model could explain respectively the kinetic and isotherm experimental data of Cu（Ⅱ） and Pb（Ⅱ） ions in single-component systems with much satisfaction.The experimental adsorption data of Cu（Ⅱ） and Pb（Ⅱ） ions in binary system were best described by the extended Freundlich isotherm and the extended Langmuir isotherm,respectively.The removal of Cu（lⅡ） ions was more significantly influenced by the presence of the coexistent Pb（Ⅱ） species,while the Pb（Ⅱ） removal was affected slightly by varying the initial concentration of Cu（Ⅱ）.The CAS was successfully regenerated using 1 mol/L HNO3 solution.

Nitrogen and Phosphorus Budget of a Polyculture System of Sea Cucumber(Apostichopus japonicus), Jellyfish(Rhopilema esculenta) and Shrimp(Fenneropenaeus chinensis)

The nitrogen(N) and phosphorus(P) budget and the ecological efficiency of a polyculture system of sea cucumber(Apostichopus japonicus), jellyfish(Rhopilema esculenta) and shrimp(Fenneropenaeus chinensis) were studied in a cofferdam, 120.2 ha in size. The nutrients were supplied by spring tide inflow. In total, 139600 kg N yr-1 and 9730 kg P yr-1 input to the system; while 118900 kg N yr-1 and 2840 kg P yr-1 outflowed from the system concurrently, thus the outflow was 85.7%(N) and 29.2%(P) of inflow. The production of N and P was 889.5 kg yr-1 and 49.28 kg yr-1(sea cucumber) and 204 kg yr-1 and 18.03 kg yr-1(jellyfish and shrimp), respectively. The utilization rate of N and P by polycultured animals was 7.8‰ and 6.9‰, respectively, 21.9% and 38% higher than that of monocultured sea cucumber. Our results indicated that the polyculture system was an efficient culture system of animals and a remediation system of coastal environment as well; it scavenged 14.3% and 70.8% of N and P, respectively. Such an ecological efficiency may be improved further by increasing either the stocking density or the size of sea cucumber or both.

EFFECTS OF CO-CULTURE AND SALINITY ON THE GROWTH AND AGAR YIELD OF GRACILARIA TENUISTIPITATA VAR LIUI ZHANG ET XIA

Gracilaria tenuistipitata var Liui were mono cultivated and co cultivated with Pinctada martensii under high (33) and low (21) salinity conditions in laboratory. The daily growth rate of the alga was determined. Tissue carbon and nitrogen contents, the yield and fractional composition of agar were analyzed. Results showed that: 1. Gracilaria grew better under low salinity conditions, the daily growth rate was twice that under high salinity conditions. Co cultivated algae grew faster than mono cultivated algae under low salinity conditions, the daily growth rate was about 37.6% higher. 2. Compared with mono cultivated algae, tissue nitrogen contents of co cultivated algae were higher, while the C:N ratios were much lower. 3. The agar yields of co cultivated algae were much lower than those of mono cultivated algae. Agar yield was found to be negatively correlated to the tissue nitrogen contents, and positively correlated to the C:N ratios. 4. The highest fractional yields obtained from co cultivated algae were extracted with 40% ethanol, while from mono cultivated algae, the highest fractional yields obtained were extracted with distilled water at room temperature.

Effects of ocean acidification on the metabolic rates of three species of bivalve from southern coast of China

Oceanic uptake of anthropogenic carbon dioxide results in a decrease in seawater pH, a process known as "ocean acidification". The pearl oyster Pinctada fucata, the noble scallop Chlamys nobilis, and the green-lipped mussel Perna viridis are species of economic and ecological importance along the southern coast of China. We evaluated the effects of seawater acidification on clearance, respiration, and excretion rates in these three species. The animals were reared in seawater at pH 8.1 (control), 7.7, or 7.4. The clearance rate was highest at pH 7.7 for P. fucata and at pH 8.1 for C. nobilis and P. viridis. The pH had little effecton the respiration rate of P. fucata and P. viridis. In contrast, the respiration rate was significantly lower atpH 7.4 in C. nobilis. The excretion rate was significantly lower at pH 7.4 than pH 8.1 for all species. Theresults indicate that the reduction in seawater pH likely affected the metabolic process (food intake, oxygenconsumption, and ammonia excretion) of these bivalves. Different species respond differently to seawateracidification. Further studies are needed to demonstrate the exact mechanisms for this effect and evaluateadaptability of these bivalves to future acidified oceans.

Occurrence and Diversity of Pichia spp. in Marine Environments

A total of 328 yeast strains from seawater, sediments, mud of salterns, the guts of marine fish and marine algae were obtained. The results of routine identification and molecular methods show that five yeast strains obtained in this study belonged to Pichia spp., including Pichia guilliermondii 1 uv-small, Pichia ohmeri YF04d, Pichia fermentans YF12b, Pichia burtonii YF11A and Pichia anomala YF07b. Further studies revealed that Pichia anomala YF07b could produce killer toxin against pathogenic yeasts in crabs while Pichia guilliermondii luv-small could produce high activity of extracellular inulinase. It is advisable to test if Pichia ohmeri YF04d obtained in this study is related to central-venous-catheter-associated infection.

Spatiotemporal distribution of protozooplankton and copepod nauplii in relation to the occurrence of giant jellyfish in the Yellow Sea

The occurrence of the giant jellyfish, Nemopilema nomurai, has been a frequent phenomenon in the Yellow Sea. However, the relationship between the giant jellyfish and protozoa, in particular ciliates, remains largely unknown. We investigated the distribution of nanoflagellates, ciliates, Noctiluca scintillans, and copepod nauplii along the transect 33~N in the Yellow Sea in June and August, 2012, during an occurrence of the giant jellyfish, and in October of that year when the jellyfish was absent. The organisms studied were mainly concentrated in the surface waters in summer, while in autumn they were evenly distributed in the water column. Nanoflagellate, ciliate, and copepod nauplii biomasses increased from early June to August along with jellyfish growth, the first two decreased in October, while N. scintillans biomass peaked in early June to 3 571 pg C/L and decreased in August and October. In summer, ciliate biomass greatly exceeded that of copepod nauplii （4.61-15.04 ~tg C/L vs. 0.34-0.89 pg C/L）. Ciliate production was even more important than biomass, ranging from 6.59 to 34.19 ~tg C/（L.d） in summer. Our data suggest a tight and positive association among the nano-, micro-, and meso-zooplankton in the study area. Statistical analysis revealed that the abundance and total production of ciliate as well as loricate ciliate biomass were positively correlated with giant jellyfish biomass, indicating a possible predator-prey relationship between ciliates and giant jellyfish. This is in contrast to a previous study, which reported a significant reduction in ciliate standing crops due to the mass occurrence ofN. nomurai in summer. Our study indicates that, with its high biomass and, in particular, high production ciliates might support the mass occurrence of giant jellyfish.

Occurrence and Diversity of Candida Genus in Marine Environments

A total of 317 yeast isolates from seawater, sediments, mud of salterns, guts of marine fishes and marine algae were obtained. The results of routine identification and molecular characterization showed that six isolates among these marine yeasts belonged to Candida genus as Candida intermedia for YA01a, Candida parapsilosis for 3eA2, Candida quercitrusa for JHSb, Can- dia rugosa for wlS, Candida zevlanoides for TJY 13a, and Candida membranifaciens for W 14-3. Isolates YA01 a （Candida intermedia）, wl8 （Candida rugosa）, 3eA2 （Candida parapsilosis）, and JHSb （Candida quercitrusa） were found producing cell-bound lipase, while isolate Wl4-3 （Candida membran（faciens） producing riboflavin. These marine yeast Candida spp. seem to have wide potential applications in bioteehnology.

Role of animal pole protuberance and microtubules during meiosis in sea cucumber Apostichopus japonicus oocytes

Fully grown oocytes of Apostichopus japonicus have a cytoplasmic protuberance where the oocyte attaches to the follicle. The protuberance and the oolamina located on the opposite side of the oocyte indicate the animal-vegetal axis. Two pre-meiotic centrosomes are anchored to the protuberance by microtubules between centrosomes and protuberance. After meiosis reinitiation induced by DTT solution, the germinal vesicle (GV) migrates towards the protuberance. The GV breaks down after it migrates to the oocyte membrane on the protuberance side. The protuberance then contracts back into the oocyte and the first polar body extrudes from the site of the former protuberance. The second polar body forms beneath the first. Thus the oocyte protuberance indicates the presumptive animal pole well before maturation of the oocyte.

Spatio-temporal variations in the siphonophore community of the northern South China Sea

To understand how hydrological and biological factors affect near-to off-shore variations in the siphonophore community,we sampled zooplankton at 82 stations in the northern South China Sea during summer,winter,and spring.Forty-one species of siphonophore were collected by vertical trawling.The species richness of siphonophores increased from the nearshore to offshore regions in all three seasons of investigation,with maximum richness in summer and minimum richness in winter.The abundance of siphonophores was also higher in summer than in spring and winter,concentrated in the nearshore region in the warm season and scattered in the offshore region in the cold season.Four siphonophore groups were classified according to the frequency of occurrence:nearshore,near-offshore,offshore,and tropical pelagic.Among them,the nearshore group had higher abundance nearshore compared with the offshore.The tropical pelagic group had higher species number offshore than nearshore.Spatial and temporal fluctuations in taxonomic composition and abundance of siphonophores were due to the influence of the coastal upwelling and surface ocean currents of the South China Sea,driven by the East Asia monsoonal system.

Species Diversity and Abundance Distribution of Pelagic Siphonophores in Nan Wan Bay of Taiwan, China, in Late Autumn and Early Winter

Zooplankton surveys were carried out on November 2-3 and December 8-10, 2001 at 12 stations in the Nan Wan Bay of Taiwan, China. Altogether 92 quantitative zooplankton samples were collected from subsurface water and bottom water layers with two conical plankton nets （180 cm in length, 45 cm in opening diameter, 333μm and 200 larn in mesh size）. A total of 31 species of Siphonophores were identified, among them 7 species are new records in the waters around Taiwan Island, of which Rocacea cymbiformis is a new record in China. Dominated by Chelophyes appendiculata, Bassia bassensis, Diphyes bojani, Diphyes dispar, Abylopsis eschscholtzi and Chelophyes contorta, these species accounted for over 76 % and 63 % of the total abundance in November and December. The species number and Siphonophores abundance in December （25 species, 1.99 inds/m3） were more than those in November （19 species, 0.438 inds/m3）, and they were more in the surface water layer than in the bottom layer at most sampling stations. In early winter, the offshore high salinity water mass was a main factor influencing the distribution. The sampling efficiency for two plankton nets is discussed and the seasonal variation of species number and abundance in the Nan Wan Bay is compared with that in the neighboring waters.

Medusa consumption and prey selection of silver pomfret Pampus argenteus juveniles

The current study explored Aurelia aurita and Rhopilema esculent um consumption by silver pomfret juveniles, as well as their prey selection between the two jellyfi sh species. Silver pomfret juveniles weighing 1±0.1 g actively preyed on both the species. Their daily A. aurita consumption was 11.6 times their own body weights regardless of the size of A. aurita medusae. Their daily R. esculent um consumption was 13, 9.1, 5, and 4.1 times their own body weights when the R. esculentum medusae were 10, 20, 30, and 40 mm in bell diameter, respectively. The survival rates of the R. esculent um were higher than those of the A. aurita. When the R. esculent um medusae were more than 30 mm in bell diameter, their survival rate exceeded 92%. Silver pomfrets serve as a type of potential predators on A. aurita in coastal waters, and they have little infl uence on R. esculent um with a size exceeding 30 mm. Besides, A. aurita may be able to be used as fi sh prey in silver pomfret artifi cial breeding.

Screen and effect analysis of immunostimulants for sea cucumber,Apostichopus japonicus

Immunostimulants may improve disease resistance of aquaculture animals by promoting the nonspecific immunity response of the organisms. Five types of saccharides, including chitosan, yeast polysaccharide, burdock oligosaccharide, seaweed polysaccharide and lentinus edodes polysaccharide, were screened for potential use as immunostimulants by using spectrophotometry. The saccharides were injected into Apostichopusjaponicus, a sea cucumber, and the lysozyme and superoxide dismutase （SOD） activities of the coelomic fluid and epidermal slime were monitored in six consecutive days. The results show that the lysozyme activity of the animal＇s coelomic fluid was significantly stimulated on day 2, day 4 and day 6 after the injection of the saccharides （P〈0.05）. The effects of chitosan and yeast polysaccharide were the most notable. The lysozyme activity of the epidermal slime was significantly increased by chitosana, yeast polysaccharide, seaweed polysacchafide, and burdock oligosaccharide on day 1 and day 2 after the injection （P〈0.05）. The SOD activity of the coelomic fluid was significantly promoted by the saccharides on day 2 and day 4 post-injection （P〈0.05）, while the SOD activity of the epidermal slime increased on day 2. These findings indicate that chitosan and yeast polysaccharide are the most effective immunostimulants and potential healthy anti-disease feedstuff for A. japonicus.

Comprehensive analysis of the origin of giant jellyfish near Qinhuangdao in summer

A massive bloom of the giant jellyfi sh Nemopilema nomurai occurred in waters off Qinhuangdao,a port city in Hebei Province,in July 2013.However,jellyfi sh larvae were not found in this location during the previous winter and spring.To determine the possible origin of the giant jellyfi sh medusa in the Bohai Sea,we developed a backward particle-tracking model and a series of numerical simulations were conducted by using the hydrodynamic,three-dimensional Regional Ocean Modeling System(ROMS)results.The simulated results showed that passive particles,representing jellyfi sh medusae,released in surface waters at diff erent dates during the summer had consistent trajectories.Particles released at the sea surface on August1 and 15 could be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and the new Huanghe(Yellow)River estuary.Particles released on July 1 and 15 could also be traced back to the center of the Bohai Sea and to waters between Feiyan Shoal and only to Zhuangxi tide station.However,none of the particles released in the middle and bottom water layers could be traced back to those areas.Based on the results of the numerical simulations,the distribution characteristics of seafl oor sediments,and observational data for giant jellyfi sh in the region,we suggest that waters between Feiyan Shoal and the new Huanghe River estuary are the likely origin of giant jellyfi sh observed near Qinhuangdao in summer.