Ecobiol aqua

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The impact of Ecobiol Aqua on shrimp performance.

A probiotic based means of boosting vegetable-based shrimp feed’s digestibility.

by Alvaro ORTIZ, MSc. Norel S.A (Spain), Ramón CASILLAS-HERNÁNDEZ, PhD. ITSON (Mexico) and Héctor NOLASCO-SORIA, PhD. CIBNOR (Mexico)

Introduction Shrimp culture is very vulnerable to many adverse effects. Diseases and the global trend to restrict the use of antibiotics at subtherapeutic doses to control them is one of the threats. Another is the availability of marine raw feed material. The FAO estimates there will be a 10% to 22% reduction on fish meal availability over the following ten years.

Sustainability in aquaculture therefore requires an increase in the usage of vegetable and land animal proteins. Although nutrient density and digestibility are the key selection criteria when looking for alternative raw mate40 FEED Business Worldwide | August 2013

rial, high digestibility is also a desirable characteristic, as it results in better nutrient utilization efficiency and thus, a superior growth rate.

With high digestibility, nutrient waste is also reduced, thereby minimizing water pollution.

Unfortunately, reduced digestibility is a common disadvantage of vegetable-based raw feed materials, and this is the main obstacle when trying to increase their inclusion. Nutritionists’ challenge nowadays is not only to fulfill nutrient requirements but also to develop new nutritional strategies that maximize nutrient utilization. Probiotics with an elevated enzyme production capacity, as Bacillus amyloliquefaciens (Ecobiol Aqua), are a viable alternative to overcome this challenge, as this enzyme activity will help animals to better digest vegetable raw materials.

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Processing stability, rapid growth and prolific enzyme output Ecobiol Aqua (Bacillus amyloliquefaciens) is commercialised in sporulated form. Structurally, it consists of several different layers (built of peptidoglycans and proteins) that reduce the spore core’s permeability and thus prevent water from entering inside the resistant cell form (Cutting, 2011; Henriques and Moran, 2007). These layers also protect the spore from light and high temperatures that could kill the microorganism. Table 1 shows how viability varies at different processing temperatures.

Bacillus amyloliquefaciens also shows an elevated growth rate. Once the spore germinates in presence of adequate conditions, its binary fission multiplication rate is faster than that of other Bacillus strains. (Fig. 1).

Their rapid colonisation is accompanied by an increase in lactic acid and barnase excretion.

The latter molecule is a ribonuclease that inhibits the growth of pathogenic bacteria. Its excretion allows the Ecobiol population to apply a strong inhibitory activity against pathogenic bacteria. Enzyme production is also increased, so nutrients in the intestinal tract are pre-digested thanks to this bacterial enzymatic activity, thereby optimizing nutrient digestion.

Many industries have already taken advantage of Bacillus amyloliquefaciens’ enzyme production capabilities. They are used to manufacture amylases used in sugar and paper processing (Zar et al. 2012), proteases used in waste treatment, in detergent and drugs manufacturing (Schallmey et al. 2004), and to make lipases, which are widely used in the production of milk by-products (Selvamohan et al. 2012).

Prolific enzyme excretion on the part active Bacillus amyloliquefaciens also makes Ecobiol Aqua interesting as a bioremediation agent. When released in the water, the en-

zymes help to break down organic matter, reducing water pollution. As shown in Table 2, Ecobiol has a better capacity to diminish COD in vitro than other Bacillus strains.

In shrimp, the hepatopancreas is an organ responsible for lipid, carbohydrates and mineral metabolism, playing a critical role in the synthesis and excretion of digestive enzymes. Its enzyme production depends on diet, the species type, season and physiological state (NRC 2011). Digestive enzymes present in the intestine are therefore synthesized in the hepatopancreas or added in the diet.

Ecobiol Aqua supplementation in shrimp diets is a means of enhancing shrimp’s enzyme activity, and with it, nutrient utilization efficiency. Ecobiol acts at three different levels: First, it compliments basal enzyme excretion with digestive bacterial enzymes synthesis. Second, by antagonizing pathogenic bacteria and discouraging their growth. Third, by improving shrimp’s growing environment by acting as a water bioremediation agent.

Trial at ITSON (Mexico) Mexico’s Sonora Technological Institute has evaluated the Ecobiol Aqua impacts the performance of shrimp (Litopenaeus vannamei) juveniles (0.85g) and pre-adults (7g). Two kg/tonne supplementation of Ecobiol was tested against a control group. Animals were placed in 10L tanks with marine filtered water, constant aeration and a controlled temperature range (30°C to 34 °C). Trials lasted 60 days.

Six replicates per treatment were used in the 0.85g shrimps trial and 3 replicates per treatment in the 7g shrimp trial. The results stated that juveniles biomass was significantly higher in the Ecobiol group from 50 days onwards (Fig. 2). Biomass tended to be higher in pre-adults at 30 days (Fig. 3).

In a second experiment at the same institute, enzyme activity was measured. Six gram animals at interAugust 2013 | FEED Business Worldwide 41

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moulting state were used in this trial. A control group was compared with the Ecobiol (2 kg/ tonne) supplemented group. Six shrimp per tank and three replicates per treatment were used.

After 12 hours fasting the animals received the feed.

Hepatopancreatic activity was measured at 6 different times after this point (0, 1, 2, 3, 4, 5 hours before feed reception); enzymatic extracts were prepared following the methodology proposed by Galgani (1983).

Protease lipase and amylase activity were determined by methodologies proposed by HernĂĄndez (1993), Versaw and Coupett (1989), and VegaVillsante et al. (1999), respectively.

Fig 4 shows how lipase activity was higher in the Ecobiol group 3 hours after feed administration whereas protease and amylase activities were higher just one hour after feed administration. These observations demonstrate how this probiotic collaborated with shrimp digestive enzyme excretion, resulting in better nutrient utilization efficiency and therefore a superior feed digestibility of the diet.

This also explains why higher shrimp biomasses were obtained in the first experiment where Ecobiol was used.

Trial at Santa Margarita Farm (Mexico) Another field trial was conducted during a whole growth period at Santa Margarita S.A. farm, which is situ42 FEED Business Worldwide | August 2013

ated in the Atanasia region, south of Sonora, Mexico. Here, the impact of Ecobiol inclusion was tested on shrimp (Litopenaeus vannamei) performance. Ten ponds of 4 hectares size were employed during this trial, which lasted approximately 120 days.

Seeding density was 14larvae/m2.

Ponds receiving Ecobiol Aqua generated 246kg more biomass compared to control ponds using the same amount of feed. Here too, the same results regarding better growth were obtained. In this particular trial, the superior shrimp performance results were obtained in commercial conditions.

Conclusion Nutrition specialists should not merely be concerned about meeting the established nutrient needs of animals. The enhanced utilization of nutrients is of great interest, as it results in improved growth and conversion rates while minimising nutrient waste and water pollution.

At a time when the aqua feed market is substituting less digestible raw materials in place of fishmeal, this priority is taking on special importance. Ecobiol’s prolific enzyme production, capacity to boost feed digestibility, balance intestinal microbiota and act as a water bioremediation agent makes it a natural, practical means of boosting the performance of shrimp fed vegetable-based nutrients.

AnimaINUTRITION References Cutting, S. M. (2011). Bacillus probiotics. Food Microbiology, 28; 214-220.

FAO (2012). The state of world fisheries and aquaculture.

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Hernández, C..M. P. (1993). Crustacean protease characterization biochemical and molecular consideration. Comprehensive summary Ph D thesis. Centro de Investigaciones Biológicas del Noroeste, la Paz, B.C.S. México, p. 26.

Li, X. Y., Zhang, J. L., and Zhu, S. W. (2011). Improved thermostable α-amylase activity of Bacillus amyloliquefaciens by low-energy ion implantation. Genetics and Molecular Research, 10; 2181-2189.

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Vega-Villasante, F., I. Fernández, R.M. Preciado, M.Oliva, D. Tovar and H. Nolasco (1999): The activity of the digestive enzymes during the molting stages of the arched swimming Callinectes arcuatus Ordway, 1863 (Crustacea:Decapoda:Portunidae). Bulletin of Marine Science, 65: 1-9.

Versaw, W.K., S.L. Cuppett, D.D. Winters and L.E. Williams (1989): An improved colorimetric assay for bacterial lipase in nonfat dry milk. Journal of Food Science, 54; 1557-1558.

Zar, M. S., Ali, S., Haq, I. (2012) Optimization of the alpha amylase production from Bacillus amyloliquefaciens IIB-14 via parameter significance analysis and response surface methodology. African Journal of Microbiology Research, 6; 3845-3855.

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