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African Journal of Pig Farming ISSN 2375-0731 Vol. 6 (2), pp. 001-006, February, 2018. Available online at 
www.internationalscholarsjournals.org © International Scholars Journals 

 

Author(s) retain the copyright of this article. 

 

Full Length Research Paper 

 

Assessment of probiotic properties of Lactobacillus 

plantarum ZLP001 isolated from gastrointestinal tract of 

weaning pigs 

 
Jing Wang, Haifeng Ji*, Dongyan Zhang, Hui Liu, Sixin Wang, Dacong Shan and Yamin Wang 

 
Institute of Animal Husbandry and Veterinary Medicine, Beijing Academy of Agriculture and Forestry Sciences, Shu 

Guang Hua Yuan Middle Road No. 9, Haidian District, Beijing 100097. 
 

Accepted 09 October, 2017 
 
The probiotic potential of Lactobacillus plantarum ZLP001, isolated from the gastrointestinal tract of a healthy 
weaning piglet, was assessed as a probiotic in vitro and in vivo. The survival rate of L. plantarum ZLP001 when 
cultured in simulated gastric fluid with pH 2.0 and 3.0 and subsequent in intestinal fluid pH 8.0 was determined and 
the results show that this strain had resistance to pH 3.0 simulated gastric fluid and subsequent pH 8.0 intestinal fluid. 
Bile salt resistance of this strain was examined in deMan, Rogosa and Sharpe (MRS) broth containing oxgall 
concentration from 0.1% to 0.5%. The strain showed 85.3 and 61.4% bile tolerance under 0.1 and 0.3% bile salt, 
respectively, and was inhibited in 0.5% bile salt (9.4%). The sizes of the inhibitory zone of this strain against 
Staphylococcus aureus, Escherichia coli, and Salmonella enterica were also determined. The result shows that this 
strain had high antimicrobial activity against selected pathogens. The probiotic strain was administered through the 
feed to 35-day old weaned piglets to estimate the effect of L. plantarum ZLP001 on the growth performance. 80 piglets 
were selected and divided into five groups comprising of negative control without any supplementation, three 
treatments of different L. plantarum ZLP001 levels (5.9×10

7
, 3.5×10

8
, and 1.8×10

9
 CFU/g of diet), and positive control 

with antibiotic treatment (chlorotetracycline, 0.3% of diet). The results of feeding trial showed that L. plantarum 
ZLP001 supplementation enhanced feed conversation rates in piglets compared with control. The present study 
implies that the strain L. plantarum ZLP001 was considered to be a potential probiotic for weaned piglets. 

  

Key words: Lactobacillus plantarum, probiotic properties, in vitro assessment, in vivo trial. 

 
INTRODUCTION 

 
Piglets are faced with many new stressors during the 
post-weaning period which can lead to the risk of 
diarrhea, reduced growth rate, changes in gut morpho-
logy and microbial population numbers and an increased 
susceptibility to disease and death (Hampson, 1994). 
Antibiotics used as feed additives in pig production  
 
 

 
*Corresponding author. E-mail: jhf309@sohu.com. Tel: +86 10 
51 503 865. Fax: +86 10 88 433 070. 

 
Abbreviations: MRS, DeMan, Rogosa and Sharpe; rRNA, 

ribosomal ribonucleic acid; CFU, colony-forming units; OD, 

optical density; BW, body weight. 

 
 
 

 
once became virtually universal owing to its obvious 
effects on growth promotion and diseases prevention. 
Along with the concerns about antibiotic residues in 
animal products increase, the potential exists for the 
implementation of a complete ban of the use of antibiotics 
in animal feed all over the world. As a consequence, the 
development of alternatives to antibiotics is receiving 
considerable attention (Turner et al., 2001). Probiotics are 
described as ‘live microorganisms which, when adminis-
tered in adequate numbers, confer a health benefit on the 
host’ (FAO/WHO, 2001). Direct-fed probiotic preparation 
plays an important role in the improving of gut microflora 
balance and consequently in the prevention of infections 
and better health condition. So, the addition of probiotics 
to the diet has gained increasing importance in pig 



 
 
 

 

nutrition in recent years and can become one potential 
alternative to antibiotic.  

The lactobacilli are major component of the gastro-
intestinal flora. Besides other bacteria, lactobacilli 
establish early in the piglet intestine and remain there as 
a predominant part of the intestinal bacterial community 
throughout the pig’s lifetime (Leser et al., 2002). The 
functional effects of lactobacilli such as protection against 
infections, stimulation of immune system, reduction of 
incidence of diarrhea have been demonstrated in many 
studies (Ouwehand et al., 2002; Koninkx and Malago, 
2008). However, not all strains of lactobacilli are equally 
resistant to the environment in the gastrointestinal tract 
and antimicrobial activity also varies between strains. 
More studies are still needed to evaluate the properties 
and effects on production performance of lactobacilli that 
comes from different sources and different strains.  

The main objective of this work was to examine the in 
vitro survival in simulated gastrointestinal condition, bile 
salt, and the ability to inhibit common porcine pathogens 
like Escherichia coli, Staphylococcus aureus and 
Salmonella enterica. of Lactobacillus plantarum ZLP001 

isolated from gastrointestinal mucosa of a healthy 
weaned piglet in our laboratory. In addition, the effects of 
the probiotic strain in vivo on the average daily weight 

gain, average daily feed intake, and feed conversion ratio 
in piglets were also determined. 
 

 
MATERIALS AND METHODS 
 
In vitro assessment 
 
Bacterial strain 
 
A probiotic lactic acid bacterial strain, L. plantarum ZLP001 was 
originally isolated from the gastrointestinal tract of a healthy 
weaning piglet in our laboratory. Strain was identified through 
standard morphological, biochemical, physiological tests and by 
16S ribosomal ribonucleic acid (rRNA) gene sequence analysis by 
the China center of industrial culture collection. Stock cultures in 
deMan, Rogosa and Sharpe (MRS) (Oxoid, UK) broth were mixed 
with 20% sterilized glycerol (v/v) at a concentration of 4:1 and 
stored at -80°C. 

 

Resistance to simulated gastric and intestinal fluids 
 
Simulated gastric and intestinal fluids were prepared as described 
by Fernández et al. (2003). Simulated gastric fluid was prepared 
fresh daily by suspending 0.35 g of pepsin in 100 ml of 0.2% saline. 
The pH was adjusted to 2.0 or 3.0 with concentrated hydrochloric 
acid, and the fluid was sterilized by filtering through 0.22 um filter. 
Simulated small intestinal fluid was prepared by suspending 0.1 g of 
trypsin and 1.8 g of bile salts in 100 ml sterile solution of 1.1 g of 
sodium bicarbonate and 0.2 g of sodium chloride. The pH was 
adjusted to 8.0 with 0.5 M sodium hydroxide. This solution was 
sterilized by filtering through 0.45 um filter.  

The bacterial strains were inoculated at 10% into the simulated 
gastric fluid at pH 2.0. The mixtures were mixed for 10 s and 
incubated at 37°C under anaerobic conditions and agitation to 
simulate peristalsis. Aliquots of this suspension were taken at 3 h, 
and the total viable count of the bacteria was determined. Then, the 

 
 
 
 

 
medium was removed by centrifugation, substituted with simulated 
intestinal fluid and incubated at 37°C anaerobically under agitation 
for additional 3 h. Determination of colony-forming units (CFU) was 
performed on MRS agar by three day incubation (37°C) in 
anaerobiosis. 

 
Bile salt resistance 
 
The effect of bile salts on the growth rate of L. plantarum ZLP001 
was determined by using the method described by Lin et al. (2007). 
The MRS broth supplemented with 0.1, 0.3, and 0.5% (w/v) oxgall, 
respectively (Oxgall bile B8381, Sigma) and without oxgall were 
freshly prepared. The overnight suspensions of the L. plantarum 
ZLP001 were inoculated (1%) into MRS broth. Bacterial cell in the 
culture broth was measured by reading the optical density (OD) at 
620 nm after 4 h incubation at 37°C. At this time point, L. plantarum 
ZLP001 strain growing in the MRS broth without oxgall was still in 
the logarithmic growth phase. The percentage of the bile tolerance 
was calculated by comparison of the OD values of the bacteria 
cultures in MRS broth with oxgall to those in MRS broth without 
oxgall. 

 
Antimicrobial activity assay 
 
The agar diffusion assay was used to test the antimicrobial activity 
of the suspending solutions of L. plantarum ZLP001 according to 
the literature (Ouoba et al., 2007) with some modifications. 
Overnight cultures of the indicator microorganisms (0.1 ml, 

approximately 10
9
 CFU/ml) were spread on 15 ml MRS agar in a 

square Petri dish. A total of 100 µl suspending solutions were 
added into the Oxford cup (a stainless cylinder, outer diameter 7.8 ± 
0.1 mm, inner diameter 6.0 ± 0.1 mm and height 10.0 ± 0.1 mm) 
which was placed on the surface of the agar. The size of the clear 
zone around the cup (including that of the ‘Oxford cup’ 7.8 mm) was 
measured and the results were reported in millimeter (mm). The 
antibacterial activities were classified as none (-), weak (+), middle 
(++), and strong (+++) inhibition, respectively, according to the 
diameters of inhibition zone of <5, >5, >10 and >15 mm (Lin et al., 
2006). The experiment was performed in triplicate. 

 
In vivo trials 
 
Pigs and diets 
 
80 piglets (Large white × Big white) with 8.35±0.79 kg initial body 
weight (BW) were selected from Beijing Jingdongyu farm (Beijing 
city, China). The pigs were weaned at 35 days of age and randomly 
allotted to five groups by initial BW. There were four replicates per 

treatment and four pigs per pen. Each pen was 1.65× 1.45 m
2
 with 

mesh floor, a feeder and a water nipple. The pig barn was 
maintained at 25 to 28°C. All pigs had free access to feed and 
water throughout the four-week feeding trial. Piglets were weighed 
and the feed intake was recorded every week in order to calculate 
average daily weight gain, average daily feed intake and feed 
conversion ratio.  

The basal diet (Table 1) mainly contained maize and soybean 
meal, and the nutrient contents met or exceeded nutrient 
requirements recommended by NRC (1998). The dietary treatments 
consisted of the basal diet with no additives, the basal diet with 
antibiotic (chlorotetracycline, 0.3% of diet), and the basal diet with 

freeze dried L. plantarum ZLP001 at 5.9×10
7
, 3.5×10

8
, and 1.8×10

9
 

CFU/g of diet. 

 
Chemical analysis 
 
The diet samples were placed in a forced-air oven at 65°C for 48 to 



  
 
 

 
Table 1. Ingredient and composition of the basal diet.  

 
 Ingredient Value 

 Maize (g/kg) 600 

 Soybean meal (g/kg) 150 

 Extruded soybean (g/kg) 60 

 Fish meal (g/kg) 50 

 Wheat bran (g/kg) 50 

 Whey (g/kg) 50 

 Premix
1
 40 

 Chemical composition  

 Digestible energy (MJ/kg) 13.76 

 Crude protein (g/kg) 182.9 

 Lysine (g/kg) 11.8 

 Methionine (g/kg) 4.2 

 Calcium (g/kg) 9.8 

 Total phosphorus (g/kg) 7.4 
 

Each kg of complete feed contains: vitamin A, 11,000 IU; vitamin D3, 3,300 IU; 
vitamin E, 16.5 mg; menadione, 3 mg; riboflavin, 7 mg; pantothenic acid, 10 mg; 
niacin, 50 mg; vitamin B12, 0.02 mg; Mn, 100 mg; Fe, 30 mg; Zn, 80 mg; Cu, 3 
mg; I, 0.75 mg; Se, 0.30 mg. 

 

 
72 h. After drying, the samples were ground through a 0.42 mm 
screen in a mill and analyzed for crude protein, calcium and total 
phosphorus by the association of official analytical chemists method 
(AOAC, 1992). The gross energy content was determined by total 
combustion of the sample with an adiabatic bomb calorimeter 
(model PARR1281, PARR Instrument Corp., US). The amino acid 
content of diet was determined by high performance liquid 
chromatography (Hitachi L-8800 Amino Acid Analyzer, Tokyo, 
Japan) according to the method of Wang et al. (2006). 

 

Statistical analysis 
 
In the in vitro assessment, the final results were expressed as the 
mean and standard deviation of three determinations. Statistical 
analysis of the obtained data in the feeding trial was carried out 
using the PROC general linear model procedure of SAS (1997). 
The pen was considered the experimental unit. Differences among 
means were tested using Tukey’s test (Zar, 1984) and probability of 
p<0.05 was used to denote significance. 
 

 

RESULTS AND DISCUSSION 

 

Resistance to simulated gastric and intestinal fluids 

 

Probiotics delivered through the feed system have to 
firstly survive during transit through the upper 
gastrointestinal tract (Huang and Adams, 2004). The 
survival rate of L. plantarum ZLP001 strains when 
cultured in simulated gastric fluid with pH of 2.0 and 3.0 
are shown in Table 2. The gastric fluid with pH 2.0 was 
inhibitory for this strain, as the number of CFU was 
reduced nearly 95% during 3 h incubation. At pH 3.0, the 

 
 

 

strain showed 81.28% survival rate after incubation after 
same time. The finding that the number of CFU was 
decreased faster at pH 2.0 gastric fluid than at pH 3.0 
was similar with the findings of Hacin et al. (2008) with 
the lactobacilli isolates from weaned piglets’ mucosa. 
Incubation of the strain in gastric fluid with pH 2.0 and 3.0 
for 3 h was an attempt to simulate the conditions that a 
probiotic would have to survive as it passes through the 
stomach of a pig. The fact that the strain kept more than 
80% viable counts after 3 h of incubation suggest that a 
reasonable percentage of the strain should survive 
passage through the harsh environment of the pig 
stomach.  

Another barrier that probiotic bacteria must survive is 
passage through the small intestine (Huang and Adams, 
2004). The treatment with simulated intestinal fluid, which 
followed the incubation in gastric fluid, resulted in 
decreased viability when the cells were previously 
exposed to low pH 2 while lightly growth was observed 
under pH 3 conditions (Table 2). The survival of strain L. 
plantarum ZLP001 was considered satisfactory since it 
was comparable to the results obtained with strain L. 
gasseri K7 which was shown to survive well in vivo in 
piglets (Rogelj and Matijaš , 2006). 
 

 

Bile salt resistance 

 

During passage through the gastrointestinal tract, 

ingested bacteria must face the challenge of toxic 

compounds such as bile. Tolerance of bile salts seems 



 
 
 

 
Table 2. Resistance of L. plantarum ZLP001 to simulated gastric and intestinal fluids.  
 

Strain 
Initial concentration 

pH of simulated gastric fluid 
Concentration after 3 h Concentration after 3 h 

 

(log CFU/ml) in gastric fluid (log CFU/ml) in intestinal fluid (log CFU/ml)  

  
 

L. plantarum ZLP001 10.26±0.15 
2 9.02±0.08 8.77±0.21 

 

3 10.17±0.12 10.29±0.04  

  
  

Presented values are means of triplicate determinations ± standard deviation from the mean. 
 
 

 

to be an important character in strains envisaged 
as probiotics to grow and survive in the upper 
small intestine (De Smet et al., 1995). Growth of 
the strain was examined in MRS broth containing 
oxgall concentration from 0.1 to 0.5% in this 
experiment. A wide variation in survival was 
observed when the strains were subjected to 
different concentration of bile salt (Table 3). After 
4 h incubation, the strain showed 85.3 and 61.4% 
bile tolerance under 0.1 and 0.3% bile salt 
respectively, and was inhibited dramatically in 
0.5% bile salt condition (9.4%) . The results of bile 
salt tolerance for L. plantarum were wide different 
owing to the different sources of strain (Jacobsen 
et al., 1999) and different methods used to 
estimate the bile tolerance (Cebeci and Gürakan, 
2003). 

 

Antimicrobial activity 
 
One of the major probiotic properties for probiotic 
lactobacilli is its inhibitory effect on the growth of 
pathogenic bacteria. L. plantarum is known to 
produce antimicrobial substances, e.g. plantaricin, 
that are active against certain pathogens (Cebeci 
and Gürakan, 2003). The size of the inhibitory 
zone for the strain against the three indicator 
pathogens is shown in Table 4. L. plantarum 
ZLP001 strain was show high inhibitory activity 
against the gram-positive bacterium S. aureus and 
the gram-negative bacteria, E. coli and S. 

 
 
 

 

enterica. These bacteria are known as the main 
pathogens causing diarrhea in piglets (Asai et al., 
2002; Fairbrother et al., 2005). Therefore, the 
strain isolated in this experiment was thought to 
have potential to compete with pathogens and 
improve the balance of the microflora in the 
gastro-intestinal tract. The production of 
antimicrobials is considered one of the major 
mechanisms through which probiotics function 
and consequently is also one of the principle 
criteria for strain selection when screening 
potential probiotics (Chang et al., 2001; Hong et 
al., 2005). It will be good to undertake further 
studies on the antimicrobial activity of the L. 
plantarum ZLP001 in order to isolate, 

characterize, and identify the antimicrobial 
compounds produced against the pathogens. 

 

Performance trials 
 
The in vitro techniques for screening L. plantarum 
as potential probiotics are far from the 
requirements in practice for farmers. The strain for 
the in vivo trial was selected primarily for the 
tolerance to low pH, bile salts and antibiotics, as 
well as antimicrobial properties. The effects of 
dietary L. plantarum ZLP001 supplementation on 
performance of weanling pigs are shown in Table  
5. Over the four-week feeding trial, piglets of 

antibiotic group consumed significant higher feeds 
than the probiotics groups (p<0.05) and no 

 
 
 

 

additive group; this is similar to the results of 
Chang et al. (2001) and it seemed to be positively 
affect the live-weight gain in them. Differences 
between probiotic groups and no additive group in 
the mean daily feed intake were not significant. 
The piglets that received diets containing L. 
plantarum ZLP001 supplements had the same 
live-weight gain daily compared with the antibiotic 
group ( p>0.05) and was significantly higher than 

the no additive group (p<0.05) except 1.8×10
9
 

CFU/g of diet supplementation diet. The result 
was different from earlier work with dose level 
dependence of Lactobacillus in broiler chickens 
performance (Choi et al., 2004). The difference 
may be due to not only the different strain and 
dose level of Lactobacillus but also to the animal 
physical condition and environment. The feed 
conversion ratio in probiotic groups were 
significantly different (p<0.05) from those of the 
antibiotic and no additive groups. The rates in 
probiotics were better than those of the control 
groups. These results indicate that in terms of 
feed consumption, the probiotic groups consumed 
10.6, 9.3, and 4.4% less than the antibiotic group 
to achieve the same weight, respectively. Similar 
observations were made by Chang et al. (2001) 
and Francisco et al. (1995) that selected probiotic 
strains had increasing effect on feed conversion 
rate in piglets. During the feed trials, some 
sporadic case of diarrhea occurred in 28.5%, 
which corresponds to the study of the incidence in 



 
 
 

 
Table 3. Effect of bile salt on the growth of the selected L. plantarum ZLP001.  

 

Strain 
OD 620 nm after 4 h incubation  Percentage of 

 

Without bile salt With bile salt 
 

tolerance (%) 
 

 

   
 

  0.1% 0.806 85.3  
 

L. plantarum ZLP001   0.945 0.3% 0.580 61.4  
 

  0.5% 0.089 9.4  
 

 

 
Table 4. The inhibition zone of L. plantarum ZLP001 when incubated with 3 indicator pathogens.  

 
 

Strain 
Inhibitory zone (mm)   

 

 
E. coli S. enterica S. aureus  

  
 

 L. plantarum ZLP001 21.58±0.4 19.88±0.5 21.00±0.8 
  

Values are the means and standard deviations of triplicate determinations; ±, standard deviation from the mean. 
 

 
Table 5. Effects on the growth performance in piglets by feeding of L. plantarum ZLP001.  

 

Parameter No additive Antibiotic 
L. plantarum ZLP001 (CFU/g of diet) 

SEM P 
 

5.9×10
7
 3.5×10

8
 1.8×10

9
  

     
 

Average daily feed intake (g/d) 660
b
 734

a
 685

b
 662

b
 674

b
 21.2 0.032 

 

Average daily gain (g/d) 357
c
 390

a
 402

a
 385

ab
 374

bc
 10.7 0.018 

 

Feed conversion ratio 1.85
a
 1.88

a
 1.70

c
 1.72

c
 1.80

b
 0.021 0.040 

  
SEM, Standard error of the mean; mean within a row, lacking a common superscript letter differ (p<0.05). 

 

 

weaning piglets as 20 to 47% (Backstrom, 1973). At the 

end of the trials, no death was recorded for the piglets. 
 
 

Conclusion 

 

The study proved L. plantarum ZLP001 for probiotic use 
in vitro by simulated gut environment tolerance tests and 
antimicrobial activity assay. The in vivo trial also 
encouraged that the use of L. plantarum ZLP001 can 
improve feed conversion ratio and live-weight gain of 
piglets. The results show that L. plantarum ZLP001 is a 

promising alternative to antibiotics for use as a feed 
additive in piglet diets. However, the exact mechanism 
through which L. plantarum may play an important role in 
the gastrointestinal tract remains uncertain, and further 
research is also needed to fully determine the exact 
mechanism through which the probiotic L. plantarum are 
achieved. 

 
REFERENCES 
 
AOAC (1992). Official Methods of Analysis, Association of Official 

Analytical Chemists. 15th Edition. Washington, DC, USA. 
Asai T, Otagiri Y, Osumi T, Namimatsu T, Hirai H, Sato S (2002). 

Isolation of Salmonella from diarrheic feces of pigs. J. Vet. Med. Sci.  
64: 159-160.  

Backstrom L (1973). Environment and health in piglet production. A field 

study of incidences and correlations. Acta Vet. Scand. Suppl. 41: 1- 

 
 

 
240. 

Cebeci A, Gürakan C (2003). Properties of potential probiotic 
Lactobacillus plantarum strains. Food Microbiol. 20: 511-518. 

Chang YH, Kim JK, Kim HJ, Kim WY, Kim YB, Park YH (2001). 
Selection of a potential probiotics Lactobacillus strain and subsequent 
in vivo studies. Antonie Van Leeuwenhoek, 80: 193-199. 

Choi YJ, Huang MK, Houde R, Lee JW, Zhao X (2004). Effects of 
Lactobacilli and an acidophilic fungus on the production performance 
and immune responses in broiler chickens. Poult. Sci. 8: 788-795. 

De Smet I, Van Hoorde L, Vande Woestyne M, Christiaens H, 
Verstraete W (1995). Significance of bile-salt hydrolytic activities of 
lactobacilli. J. Appl. Microbiol. 79: 292-301. 

Fernández MF, Boris S, Barbés C (2003). Probiotic properties of human 
lactobacilli strains to be used in the gastrointestinal tract. J. Appl. 
Microbiol. 94: 449-455. 

Hacin B, Rogelj I, Matijasic BB (2008). Lactobacillus isolates from 
weaned piglets’ mucosa with inhibitory activity against common 
porcine pathogens. Folia Microbiol. 53: 569-576. 

Hampson DJ (1994). Postweaning Escherichia coli diarrhea in pigs.  
Gyles C L (ed.): Escherichia coli in Domestic Animals and Humans.  
London: CABI, 171-791.  

Huang Y, Adams MC (2004). In vitro assessment of the upper 
gastrointestinal tolerance of potential probiotic dairy propionibacteria. 
Int. J. Food Microbiol. 91: 253-260. 

Fairbrother JM, Nadeau E, Gyles CL (2005). Escherichia coli in 
postweaning diarrhea in pigs: an update on bacterial types, 
pathogenesis, and prevention strategies. Anim. Health Res. Rev. 6: 
17-39.  

FAO/WHO, Evaluation of health and nutritional properties of probiotics 
in food. Including power milk with live lactic acid bacteria, Report from 
FAO/WHO Expert Consultation, 1-4 October 2001, Cordoba, 
Argentina, 2001.  

Francisco T, Juan R, Erenia F, Maria LR (1995). Response of piglets to 

oral administration of lactic acid bacteria. J. Food. Protect. 58: 1369-

1374. 



 
 
 

 
Hong HA, Duc le H, Cutting SM (2005). The use of bacterial spore 

formers as probiotics. FEMS Microbial Rev. 29: 813-835. 
Jacobsen CN, Rosenfeldt Nielsen V, Hayford AE, Møller PL, 

Michaelsen KF, Pærregaard A, Sandström B, Tvede M, Jakobsen M 
(1999). Screening of probiotic activities of forty-seven strains of 
Lactobacillus spp. by in vitro techniques and evaluation of the 
colonization ability of five selected strains in humans. Appl. Environ. 
Microbiol. 65: 4949-4956. 

Koninkx JFJG, Malago JJ (2008). The protective potency of probiotic 
bacteria and their microbial products against enteric infections. Folia 
Microbiol. 53: 189-194. 

Leser TD, Amenuvor JZ, Jensen TK, Lindecrona RH, Boye M, Møller K 
(2002). Culture-independent analysis of gutbacteria: the pig 
gastrointestinal tract microbiota revisited. Appl. Environ. Microbiol. 68: 
673-690.  

Lin WH, Hwang CF, Chen LW, Tsen HY (2006). Viable counts, 
characteristic evaluation for commercial lactic acid bacteria products. 
Food Microbiol. 23: 74-81. 

Lin WH, Yu B, Jang SH, Tsen HY (2007). Different probiotic properties 
for Lactobacillus fermentum strains isolated from swine and poultry. 
Anaerobe, 13: 107-113. 

NRC (1998). National Research Council. Nutrient Requirements of 
Swine. 10th Edition. National Academic Press. Washington, DC, 
USA. 

Ouoba LII, Diawara B, Jespersen L, Jakobsen M (2007). Antimicrobial 
activity of Bacillus subtilis and Bacillus pumilus during the 

fermentation of African locust bean (Parkia biglobosa) for Soumbala 
production. J. Appl. Microbiol. 102: 963-970. 

 
 
 
 

 
Ouwehand A, Salminen AC, Isolauri E (2002). Probiotics: an overview of  

beneficial effects. Antonie van Leeuwenhoek, 82: 279-289.  
Rogelj I, Matijaš BB (2006). Lactobacillus gasseri LF221 and K7-from 

isolation to application. Biologia, 61: 761-769.  
SAS (1997). SAS/STAT User’s Guide, Version 9. SAS Institute Inc. 

Cary, NC, USA. 
Turner JL, Dritz SS, Minton JE (2001). Review: alternatives to 

conventional antimicrobials in swine diets. Prof. Anim. Sci. 17: 217-
226. 

Wang X, Qiao SY, Liu M, Ma YX (2006). Effects of graded levels of true 
ileal digestible threonine on performance, serum parameters and 
immune function of 10-25 kg pigs. Anim. Feed Sci. Tech. 129: 264-
278.  

Zar JH (1984). Biostatistical Analysis. 2nd Edition. Prentice-Hall, 

Englewood Cliffs, NJ, USA. 


