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。

complete ready / retreieved from http://faculty.stust.edu.tw/~c5200999/%C1%BF%B8q/%A4W%BA%F4%C1%BF%B8q%A2w04%20%BB%C3%A5%C0%B5%DF%A4%C0%C3%FE.pdf

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