The Yeast 酵母菌 ( Yis )

The Yeast 

酵母菌 

根據荷蘭Lodder & Kreger-van Rij 所著 

“The Yeasts, A Taxonomy Study”

 分類主要依據是： 

1. 形態 
2. 對硝酸鹽或碳源的利用 
3. 對糖的發酵性 

形態與大小：
因酵母種類不同而不同，同 一種也會因培養條件或發育 時期不同而有異，一般直徑 約在5 µm，顯微鏡40X及 100X接物鏡下皆可觀察到。

增殖法：
主要為營養增殖(出芽生殖 (budding))，偶而行子囊胞子 (ascus and ascospore)來增殖。

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For mass production of nematode Panagrellus redivivus, brewer’s yeast is suitable as food source.

Fish Production

Although aquaculture in world is increasing constantly, it is still facing problems due to limited supply of raw material for fish feed (Tacon and Metian, 2008). For promoting normal growth of fish, proper nutrition plays a key role. In certain fish production, Brewer’s yeast is used as a fish feed (Nayar et al. 1998). Food industries (e.g. dairies and slaughterhouse) release waste-water, which contains considerable amounts of proteins and fats. Conversion of fat into yeast biomass could be beneficial, because yeast biomass can be use as fish feed. Different carbon sources including glycerol have been used for the highest growth yield of C. trophicals (Rydin et al. 1990). Brewer’s yeast has different immunostimulating compounds e.g. nucleic acid, b-glucans and mannan oligosaccharides (White et al. 2002). These compounds may enhance growth of different fish species and therefore can serve as best health promoters for fish culture (Lara-Flores et al. 2002). For mass production of nematode Panagrellus redivivus, brewer’s yeast is suitable as food source. This nematode is used as a source of food for feeding farm fish (Ricci et al. 2003).

continue read from http://stud.epsilon.slu.se/3578/1/Fawad%20Khan%20201112.pdf

LARVAL FEED ALTERNATIVES INTRODUCTION

LARVAL FEED ALTERNATIVES 
Phil Boeing 

CONTENTS
• Introduction
• Algae Rotifers
• Artemia nauplii
• Ongrown Artemia
• Nematodes
• Crustacean
• Tissue Suspension
• Summary
• Rotifers
• Artemia nauplii
• Nematodes Algae
• Crustacean tissue suspension
• Recommendations


INTRODUCTION 

There are two major reasons why non-living produced feeds for rearing larvae of aquatic animals do not yet have an advantage over live food organism. These are: rapid deterioration of water quality due to disintegration of micropellets, which are usually fed in excess in order to achieve satisfactory growth and survival; high mortality rates, due to malnutrition and/or incomplete digestion of diet components. Cultivation of larval stages of various aquaculture species is still highly dependent on live food which is for herbivorous larvae, like molluscs and crustaceans, a fairly understood task. Many more difficulties have to be faced when live food animals are required, as is mainly the case in fish rearing, but holds true for latter stages of crustacean larvae as well. The reason why live food is so essential for larval growth has not yet been clearly defined. Enzymes present in phyto and zooplankton but not synthesized by the physiological system of a larvae are probably important. Also of importance are several essential biochemical compounds such as poly-unsaturated fatty acids, most of which have been defined as to species requirements. Primary producers of these fatty acids such as algae and bacteria form the base of the trophic pyramid, and as such constitute the largest link in the aquatic food chain. The largescale, intensive production of microalgae and rotifers suffers from two major problems: it is expensive and often unreliable. Contributing to the problem is the fact that designs used for experimental and pilot scale units, which are the bulk of the published research, are usually inappropriate for larger system because of logistical problems, prohibitive cost of materials, or diminishing surface area to volume relationships which affect scale up performance. Scale up problems can arise in the bulk handling of materials such as animals, water and feeds which in a restricted laboratory situation are easily transported and held in small containers. Carrying out necessary life support functions can also become complicated, since daily work routines for large numbers of animals quickly becomes prohibitive. Routine maintenance and cleaning of culture units, while trivial in the laboratory becomes a major problem with increased scale. As hatchery managers try to stem the rising costs of production, the economic cultivation of live feeds or some alternative becomes ever more important. The sections that follow will attempt to illuminate various options and potentials for larval penaeid shrimp feeds. The summary section will then rate the most cost effective choices for management consideration.

continue read from http://www.aquafauna.com/LARVAL%20FEED%20ALTERNATIVES.pdf

Improving nematode culture techniques and their effects on amino acid profile with considerations on production costs ( tested with of 11 different culture media )

By B. H. Buck1,2, J. Bruggemann € 3 , M. Hundt4 , A. A. Bischoff5 , B. Grote1 , S. Strieben1 and W. Hagen6 

1 Alfred Wegener Institute, Helmholtz Center for Polar and Marine Research (AWI), Bremerhaven, Germany; 2 University of Applied Science, Bremerhaven, Germany; 3 Institute for Marine Resources (IMARE), Bremerhaven, Germany; 4 Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany; 5 Lehrstuhl fur Aquakultur und Sea-Ranching, € Agrar- und Umweltwissenschaftliche Fakultat der Universit € at Rostock, Rostock, Germany; € 6 Marine Zoology, University of Bremen, Bremen, Germany

In recent years several species of nematodes have been identified as possibly suitable alternatives to Artemia nauplii (Bruggemann, 2012). The non-parasitic soil nematode € Panagrellus redivivus has received particular attention. This nematode can reproduce rapidly and provide large biomass yields (Ricci et al., 2003). According to Wilkenfeld et al. (1984), the production is about 30% cheaper compared to Artemia culture. Additionally, the fatty acid profiles and the lipid contents are extremely variable, depending on the culture media used (Schlechtriem et al., 2004a,b), in P. redivivus between 2.7 and 39.8% with regard to the total lipid content (Rouse et al., 1992; Schlechtriem et al., 2005). The amino acid profile of this nematode species is similar to Artemia (Biedenbach et al., 1989; Lavens and Sorgeloos, 1996; Santiago et al., 2003) and to frozen zooplankton (Schlechtriem et al., 2004b). These advantages pr

These advantages prompted aquaculturists to evaluate the suitability of P. redivivus as a live food for feeding to different types of fish and/or shrimp. It has been shown that the use of P. redivivus in co-feeding regimes of the common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix) can enhance larval growth in comparison to larvae fed a dry diet. Kahan et al. (1980) and Schlechtriem et al. (2004a) found that P. redivivus led to decent survival rates in larvae of common carp (C. carpio). However, it must be noted that although P. redivivus seems to reach acceptable performance rates in feeding regimes of some fish species, most studies show that the survival and growth is lower than in fish fed with Artemia nauplii (see Bruggemann 2012, for € details).

Regarding the feeding of shrimp larvae in contrast to fish larvae, nematode performance is shown to be equal or even superior compared to Artemia nauplii. Biedenbach et al. (1989) raised Pacific white shrimp (Litopenaeus vannamei) larvae on nematodes and showed that the larvae fed with different nematode densities grew faster or were at least similar in comparison to an Artemia diet. Also in Pacific white shrimp larvae, Focken et al. (2006) showed that there was little difference in survival when fed either nematodes or Artemia and that larvae grew almost as fast as with Artemia in high enough nematode densities (100–150 Ind. ml1 ). Wilkenfeld et al. (1984) found nematodes to be an excellent food for larvae of northern brown shrimp (Farfantepenaeus aztecus), northern white shrimp (Litopenaeus setiferus), as well as Paci- fic white shrimp. Culture performance of shrimp larvae could also be improved by improving the fatty acid profiles of nematodes by enrichment with different types of oils (Kumlu et al., 1998). Nematodes (+algae) led to higher survival rates in Indian prawn (Fenneropenaeus indicus) than with a diet of algae and Artemia.


Full infomation / Retrieved from https://epic.awi.de/37703/1/Buck_2015_JAI.pdf

Attraction of Nematodes to Living Mycelium of Nematophagous Fungi

RESULTS 

Determination of attraction and repulsion 

A typical result of an attraction test with the nematophagous fungus Arthrobotrys musiformis is shown in Table 1. On average, 75 % of the nematodes were found under the discs of attracting fungi in quadrants I and I11 after 24 h. Of the 14 nematophagous fungi tested, 10 attracted P. redivivus (Table 2). Only one fungus, A. arthrobotryoides, with spontaneously formed traps, repelled the nematodes, Arthrobotrys dactyloides and D. gracilis, both with constricting ring traps, neither attracted nor repelled the nematodes. The same result was found with A. conoides, which did not form traps spontaneously. All three strains of A. oligospora showed moderate attraction, irrespective of the presence or absence of spontaneously formed traps. Of the nine non-nematophagous fungi tested, five attracted and one repelled the nematodes (Table 2).


Determination of attraction intensity 

The three groups of nematophagous fungi were tested for their attraction intensity. The endozoic parasite (H. anguillulae) always showed the highest attraction intensity (slope > 6). Group 2, with the slow-growing attracting fungi M. ellipsosporum, M. cionopagum and D. candida, showed a somewhat lower attraction (slope 3 to 6), while the fast-growing species (group 1) had the lowest attraction intensity (slope < 3). The non-nematophagous fungi tested (Trichothecium roseurn, Verticillium dahliae, Mortierella parvispora and Penicillium spinulosum) also showed low attraction intensities. Figure 1 shows examples of these differing responses.

Results from one experiment with several members of groups 1 and 2 are shown in Fig. 2. The difference in attraction intensity between the two groups is evident. In a parallel experiment, each slow-growing fungus (group 2) was tested against a fast-growing fungus (group 1) on the same plate (e.g. M. ellipsosporum versus A. oligospora, M. cionopagurn versus A. mus$ormis etc.). After 6 h the nematodes under each disc were counted. Once again, members of group 2 attracted more nematodes than those of group 1 (P < 0.01, five replicate plates). Although the slow-growing group 2 fungi had traps, which the fast-growing group 1 fungi lacked, very few nematodes were captured during this 6 h period. The higher attraction intensity of the fungi in group 2 could therefore not have been due to capture by the traps.


Eflect of u.v.-irradiation 

To determine if the attraction/repulsion pattern of the nematophagous fungi shown in Table 2 was confined to living fungi, attraction tests were done after killing the fungi with u.v.-irradiation. After irradiation, group 1 fungi and non-nematophagous fungi no longer attracted nematodes but the slow-growing fungi (groups 2 and 3) still did so (Table 2). Repulsion and neutral responses to the other fungi remained unchanged.


DISCUSSION 

The assay used in this investigation allowed us not only to detect attraction or repulsion, but also to determine differences in the attraction intensity of different fungi; in both cases it gave reproducible results.

Field & Webster (1 977), studying attraction to living mycelium of five nernatophagous Downloaded from www.microbiologyresearch.org by IP: 192.198.147.164 On: Wed, 08 Mar 2017 08:07:06 Attraction of nematodes to fungi 93 fungi with different types of traps, showed that fungi stimulated to trap formation with horse serum or nematode extract attracted both a Rhabditis sp. (bacteria-feeding) and the fungusfeeding Aphelenchus avenae, whereas the unstimulated fungi did not. They concluded that attraction was dependent on the presence of traps. -We have shown that the presence of traps does not necessarily cause attraction, and one trap-forming fungus, A. arthrobotryoides, even repelled the nematodes. Further, the constricting ring forms (A. dactyloides and D. gracilis) neither repelled nor attracted the nematodes (Table 2). An explanation for these differing results might be that substrate composition affects the attractiveness of the fungi. Addition of proteinaceous trap-inducing materials, such as horse serum or nematode extract, may result in attracting excretion products, not necessarily coupled to trap formation.

When the fungi were killed by u.v.-irradiation before nematodes were added, the attraction of group 1 fungi was completely abolished. The attracting fungi of groups 2 and 3 were still attractive, although somewhat less so, after such treatment. This suggested that a volatile substance, or a small rapidly diffusing compound, continuously produced, was responsible for attraction to the fast-growing fungi. With the fungi of groups 2 and 3, larger or less volatile, slowly diffusing compounds might be responsible for attraction. The non-nematophagous fungi resembled the fast-growing nematophagous fungi in this respect. However, the substances responsible for attraction are unknown.

Cooke (1963) concluded that rapid growth rate and good saprophytic ability were accompanied by lower predacious efficiency. In our study, the attraction intensity was lowest in fungi with moderate or high saprophytic ability (Table 2, group 1 and the nonnematophagous fungi). The u.v.-irradiation tests also showed a similarity between these fungi, Attraction intensity increased with increasing parasitism of the fungi in groups 2 and 3. It therefore appears that the attraction intensity reflects the dependence of the fungi on nematodes for nutrients. The gift of Harposporiurn anguillulae from Dr G. L. Barron, University of Guelph, Canada, is gratefully acknowledged. This investigation was supported by the Swedish Natural Science Research Council. R

Infomation Retreived from http://www.microbiologyresearch.org/docserver/fulltext/micro/112/1/mic-112-1-89.pdf?expires=1488961325&id=id&accname=guest&checksum=E8BEAE637E2380FFFA3AF000B2B4C472

Mass Culture of Axenic Nematodes Using Continuous Aeration

By EDWARD J. BUECHER 2 AND EDER L. HANSEN


Biochemical and physiological studies of nematodes often require sufficient material for analysis (5, 6). Two important limitations of axenic culture methods are the need for proteinaceous components (1, 8) and proper gas exchange (9). Proteinaceous supplements are tedious to prepare. Suitable gas exchange is obtained by using thin layers of medium (9), necessitating glassware of considerable size if large populations are desired.

The plant-parasitic nematode Aphelenchus avenae can withstand vigorous aeration in buffer (3). When air was continuously bubbled through a culture of A. avenae in 20 ml of a defined medium supplemented with fresh chick embryo extract and serum (7), the population increased from 400 to 11,000 per ml in 4 weeks. This aeration system was therefore applied to mass culture of other nematodes.

The free-living nematodes Caenorhabditis elegans, Turbatrix aceti, and Panagrellus redivivus, and the insect-parasitic nematodes Neoaplectana glaseri and N. carpocapsae (DD136 strain) were tested for growth under continuous aeration. Sufficient air flow was bubbled through the medium to continuously mix the nematodes. Air was sterilized by passage through a Millipore DA gas filter. Gas washing bottles (Kontes Glass Co., Vineland, New Jersey) of 125, 250, or 500ml with open-end dispersion tubes were used as the culture vessels. The basal medium consisted of 3% soy peptone, 3% yeast extract (4), and 0.7% dextrose; it was autoclaved for 20 min at 121 C. MEM vitamins® 100 × solution (Grand Island Biological Co., Grand Island, New York), 5 ml per 100 ml of medium, and autoclaved antifoam emulsion Y-30® (Dow Coming Corp., Midland, Michigan), 0.2 ml per 200 ml of medium, were added aseptically. Filtered preparations of heated liver extract (10) or yeast extract ( 1 ) were added as supplements of 5 to 10 mg per ml; medium containing yeast extract was adjusted to pH 3.8 with glacial acetic acid. When either sodium caseinate (Nutritional Biochemicals Corp., Cleveland, Ohio) (W. Hieb, personal communication) or glycogen (Fisher Scientific Co., New York, New York) was used as the supplement, it was added at 10 mg per ml and autoclaved with the basal medium. Filtered hemin chloride (2) was then added at l0 ~g per ml.

The inoculum size varied from 30 per ml for N. carpocapsae to 2,000 per ml for T. aceti; cultures were incubated at room temperature (20 to 25 C). Growth was determined from nematode counts; the final count was made after 3 weeks when no further increase in population was observed. The resuiting populations are summarized in Table 1. Each species went through one or two generations. Counts were up to 10 times greater than in control test tube cultures, and increased up to 600-fold over the inoculum.

Weights of lyophilized nematodes from the 170-ml liver-supplemented cultures were 500 to 720 mg. The 500-ml culture of C. elegans yielded a wet weight of 5 g and a lyophilized weight of 1 g of nematode tissue. Stoll obtained high populations of N. glaseri with shaking of 3,5 mm-deep cultures (11). In a 100-ml culture with constant aeration we obtained a twofold increase in population (Table 1). The protein used, 5 mg per ml, was lower than optimum for this species.


Constant aeration appears to remove ammonia and thus retard a rise in pH and subsequent death noted in test tube cultures. In mass cultures less than 1% of the nematodes were dead at harvest compared to 50% in test tube controls. Exceptions were cultures of C. elegans in sodium caseinate medium, in which 10% were dead, and T. aceti in yeast medium, in which 4% were dead.

The tedious task of preparing protein extracts can be eliminated by using glycogen or sodium caseinate. Sodium caseinate is particularly useful in that it is an autoclavable, inexpensive, commercially available supplement that supports high nematode populations. It also supported maturation of C. briggsae, C. elegans, P. redivivus, T. aceti and N. carpocapsae in test tube cultures.

Retreived from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2619865/pdf/199.pdf

The nutritional quality of nematodes ( Microworm ) can be enhanced by the use of the bio-encapsulation technique

Nematodes 

The use of the free living nematode, Panagrellus redivivus ( Common name : Microworm ) as larval food has been demonstrated successfully for several species, including Crangon crangon, juvenile king shrimp (Penaeus blebejus), common carp (Cyprinus carpio) and silver carp (Hypophthalmichthys molitrix). 

P. redivivus is a suitable larval live food since it is small (50 µm in diameter). Moreover, it has an amino acid profile that matches that of Artemia (Table 6.2.), while its EPA and DHA content is respectively nearly a third and almost the same or a little higher of that of Artemia, (Table 6.3.). P. redivivus can be cultured very simply in trays filled with 70 g of flour (10.8% protein) per 100 cm2 , the latter kept humid by spraying with water. The culture medium is supplemented weekly with 0.5 g baker’s yeast per 100 cm2 , which should inhibit the growth of nematophage fungi. The containers should be stored in a well ventilated room at a temperature of 20-23°C. Contamination by insects can be prevented by covering the containers with cloth. The nematodes are harvested daily for about 53 days using the same culture medium by removal from the substrate with a spatula (Fig. 6.2.). A maximum daily production of 75-100 mg per 100 cm2 is reached at week 3. For smaller cultures the nematodes can be harvested by adding a small quantity of distilled water to the trays and decanting the suspended nematodes. The nematodes have a short generation time ranging from 5-7 days and a high fecundity. 290 Table 6.2. Comparison between the protein and amino acid compos

The nutritional quality of nematodes can be enhanced by the use of the bio-encapsulation technique. Enrichment is simply carried out by adding the product to the culture medium (direct enrichment) or by bringing the nematodes in an emulsion of the product (indirect enrichment). Rouse et al. (1992) used for the direct enrichment a culture medium which was fortified with a 10% fish oil emulsion, obtaining nematodes that had a significantly higher total lipid content and elevated levels of (n-3) HUFA (i.e. 11.2% and 4.8% respectively; Table 6.3.).

The bioencapsulation technique can also be used to fortify the nematodes with therapeutics (bio-medication). For example, nematodes can be placed in 1 l beakers with 500 ml of fresh artificial seawater and 5 g of Romet-30 premix (Hoffman - La Roche, Switzerland) containing 25 % sulfadimethoxine, 5 % ormetoprim and 70 % rice bran carrier. After a 4 h boost period, during which the nematodes have accumulated 0.25 µg of the drug per individual (0.1 µg.ind.-1 for Artemia nauplii), the nematodes are separated from the antibiotic carrier by resuspension in seawater and centrifugation at 1500 rpm for 10 min. After a 10-20 min period the animals have migrated to the top of the tube, where they can be collected with the use of a pipet onto a 100 µm mesh screen. After rinsing with seawater, the nematodes can then be fed to the larval predators.

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