Elsevier

Process Biochemistry

Volume 48, Issue 4, April 2013, Pages 559-568
Process Biochemistry

Gamma-aminobutyric acid production in black soybean milk by Lactobacillus brevis FPA 3709 and the antidepressant effect of the fermented product on a forced swimming rat model

https://doi.org/10.1016/j.procbio.2013.02.021Get rights and content

Abstract

Despite the prevalence and severe effects of depression, the efficacy of currently available antidepressants is often inconsistent, and many exert undesirable side effects. Administration of food containing gamma-aminobutyric acid (GABA) has been proposed as an alternative treatment for depression. Therefore, this study ferments soy-based milk enriched in GABA and tests its anti-depressant activity in Sprague-Dawley (SD) rats. First, Lactobacillus brevis FPA 3709 isolated from fish intestine was selected for its ability to produce GABA during cultivation in MRS broth with monosodium glutamate (MSG). Second, the conditions (substrate composition and treatment, initial pH, and time and temperature of fermentation) for obtaining the highest synthesis of GABA by the selected microorganism were established. Finally, cooked black soybean milk supplemented with 1% MSG, 1% brown sugar, and 0.1% peptone (without adjusting the initial pH level) was fermented (37 °C, 48 h) by L. brevis FPA 3709. SD rats subjected to a forced swimming test (FST) and fed with fermented black soybean milk showed immobility times that were not significantly different from that of rats administered with fluoxetine, a common antidepressant drug, without exhibiting the side effects of lost appetites and reduced body weight typical of fluoxetine use. Fermented black soybean milk enriched with GABA is a good candidate as an alternative treatment of depression.

Highlights

► One strain, Lactobacillus brevis FPA 3709, from 126 lactic acid bacteria isolated from fish intestines was chosen for GABA production. ► FPA3709 produces a very high amount of GABA in formulated black soybean milk at 37 °C for 48 h. ► The 48-h fermented product has similar antidepressant activity as fluoxetine but without side effects caused by fluoxetine.

Introduction

Depression is a widespread incapacitating psychiatric ailment ranked by the World Health Organization (WHO) as one of the most burdensome diseases of society [1], [2]. Despite the prevalence and severe effects of this disease, the efficacy of the currently available antidepressants is often inconsistent, and many exert undesirable side effects.

Gamma-aminobutyric acid (GABA), a 4-carbon non-proteinaceous amino acid found ubiquitously in nature, has various physiological functions, such as hypotensive [3], hypoglycemic [4], and anticancer activities [5]. Several studies have recently demonstrated that the dysfunction of GABAergic neurons, which are responsible for GABA production, is involved in depression [6], [7], [8], anxiety [9], and Alzheimer's disease [10]. Depressed patients show significantly reduced activity of GABAergic neurons in the prefrontal or occipital cortex, leading to greatly decreased GABA levels in these 2 areas and in the plasma and cerebrospinal fluid of depressed patients [11], [12], [13]. Therefore, searching for GABA-rich foods has become a relevant topic in the field of functional foods. Researchers have developed numerous GABA-rich products, such as GABA tea [14], [15], germinated crops, including brown rice [16], barley [17], and wheat [18], red mold rice [19], [20], and various fermented foods produced by GABA-producing lactic acid bacteria (LAB) [21], [22], [23].

Researchers have reported GABA-producing LAB strains from various sources, including Lactobacillus lactis subsp. lactis from kimchi [24], Lactobacillus brevis from alcohol distillery lees [25], Lactobacillus paracasei from fermented fish [26], and L. delbrueckii subsp. bulgaricus from cheese [27]. Researchers have also sequenced their genes for glutamic acid decarboxylase (GAD), which catalyze the decarboxylation of l-glutamate for GABA synthesis.

The LAB currently used in the food industry are mainly isolated from human feces [28], plants [29], and various fermented products, such as kimchi [23], [30], cheese [27], tempeh [31], and sausage [32]. Only a few LAB have been isolated from fish intestines [33]. The aims of this study are as follows: to isolate LAB from fish intestines and select the highest GABA-producing LAB isolate; to establish the ideal bean milk among 3 tested samples of black soybean, soybean, and red bean milk as the basal substrate; to optimize the culture conditions to increase the concentration of GABA produced during fermentation by LAB isolate and to test, using a forced swimming test (FST), the antidepressant effect of fermented bean milk after orally feeding it to Sprague-Dawley (SD) rats.

Section snippets

LAB isolation from fish intestines

Fifteen fish samples (Priacanthus macracanthus, Psenopsis anomala, Pseudosciaena polyactis, Lateolabrax japonicas, Cololabis saira, Calotomus carolinus, Scomber australasicus, Kuhlia rupestris, Leopard coralgrouper, Taius tumifrons, Priacanthus macracanthusthu, Pampus agrenteus, Branchiostegus japonicas, Epinephelus malabaricus, and Polydactylus plebeius) were purchased from local fish markets in Keelung, Taiwan. The fish were kept in an icebox and immediately transferred to the laboratory.

LAB isolation from fish intestines and screening for isolates with GABA production

The experiments in this study involved analyzing 126 LAB isolates from 15 fish samples. All of these isolates were confirmed to be Gram-positive, catalase-negative, and oxidase-negative, and produce sufficient acid (data not shown), which are the basic characteristics of LAB.

The GABA production of 126 LAB isolates in MRS with 5% MSG was screened by TLC. Fig. 1 shows the TLC profiles of certain representatives. The isolates with a visible band of GABA are FPP3713, FPA3709, FKR3737, FKR3739, and

Discussion

Although GAD is widely found in LAB [41], the GABA-producing capability of LAB may vary between strains. Previous studies have isolated GABA-producing LAB from cheese and dairy products [27], [41], wine spent [25], and fermented kimchi products [23], [36], [42]. This is the first study to report on the isolation of GABA-producing LAB from fish intestines for application in food fermentation.

Cooking treatment by heating soaked bean grains in water at 100 °C for 50 min may soften the bean, which

Conclusion

Cooked black soybean milk was an ideal basal substrate for GABA production by L. brevis FPA 3709 isolated from fish intestine. FPA3709 produced a high amount of GABA (5.42 ± 0.39 mg/mL) in cooked black soybean milk with 1% MSG, 1% brown sugar, and 0.1% peptone without pH control after incubation at 37 °C for 48 h. This 48-h fermented black soybean milk had an antidepressant effect similar to that of fluoxetine, but without the side effects of lost appetite and decreased weight. The underlying

Acknowledgments

The authors gratefully acknowledge the financial support of the National Science Council of Taiwan, R.O.C. (NSC98-2313-B-019-010-MY3) and the Center of Marine Bioenvironment and Biotechnology, National Taiwan Ocean University (NTOU-RD-AA-2012-102011).

References (60)

  • S. Yokoyama et al.

    Production of gamma-aminobutyric acid from alcohol distillery lees by Lactobacillus brevis IFO-12005

    J Biosci Bioeng

    (2002)
  • N. Komatsuzaki et al.

    Production of gamma-aminobutyric acid (GABA) by Lactobacillus paracasei isolated from traditional fermented foods

    Food Microbiol

    (2005)
  • W. Noonpakdee et al.

    Isolation of nisin-producing Lactococcus lactis WNC 20 strain from nham, a traditional Thai fermented sausage

    Int J Food Microbiol

    (2003)
  • R. Hartemink et al.

    LAMVAB—a new selective medium for the isolation of lactobacilli from faeces

    J Microbiol Methods

    (1997)
  • V. Vanos et al.

    Rapid routine method for the detection of lactic acid bacteria among competitive flora

    Food Microbiol

    (1986)
  • S. Moret et al.

    HPLC determination of free nitrogenous compounds of Centaurea solstitialis (Asteraceae), the cause of equine nigropallidal encephalomalacia

    Toxicon

    (2005)
  • Y. Xu et al.

    Antidepressant effects of curcumin in the forced swim test and olfactory bulbectomy models of depression in rats

    Pharmacol Biochem Behav

    (2005)
  • M. Nomura et al.

    Production of gamma-aminobutyric acid by cheese starters during cheese ripening

    J Dairy Sci

    (1998)
  • K.B. Park et al.

    Production of yogurt with enhanced levels of gamma-aminobutyric acid and valuable nutrients using lactic acid bacteria and germinated soybean extract

    Bioresour Technol

    (2007)
  • J.S. Tsai et al.

    Antihypertensive peptides and gamma-aminobutyric acid from prozyme 6 facilitated lactic acid bacteria fermentation of soymilk

    Process Biochem

    (2006)
  • E. Caplice et al.

    Food fermentations: role of microorganisms in food production and preservation

    Int J Food Microbiol

    (1999)
  • C.P. O’Byrne et al.

    The role of SigB in the stress adaptations of L. monocytogenes: overlaps between stress adaptation virulence

  • I.L. Jung et al.

    Polyamines and glutamate decarboxylase-based acid resistance in E. coli

    J Biol Chem

    (2003)
  • F. Borsini

    Role of the serotonergic system in the forced swimming test

    Neurosci Biobehav Rev

    (1995)
  • E.R. Duke et al.

    Effects of heat stress on enzyme activities and transcript levels in developing maize kernels grown in culture

    Environ Exp Bot

    (1996)
  • S.B. Patten

    Major depression prevalence is very high, but the syndrome is a poor proxy for community populations’ clinical treatment needs

    Can J Psychiatry

    (2008)
  • H. Aoki et al.

    Effect of gamma-aminobutyric acid-enriched tempeh-like fermented soybean (GABA-tempeh) on the blood pressure of spontaneously hypertensive rats

    Biosci Biotechnol Biochem

    (2003)
  • T. Nakagawa et al.

    Protective effects of gamma-aminobutyric acid in rats with streptozotocin-induced diabetes

    J Nutr Sci Vitaminol

    (2005)
  • H. Watanabe et al.

    Tissue-specific estrogenic and non-estrogenic effects of a xenoestrogen, nonylphenol

    J Mol Endocrinol

    (2004)
  • P. Brambilla et al.

    GABAergic dysfunction in mood disorders

    Mol Psychiatry

    (2003)
  • Cited by (117)

    • Metabolomics and the Gut–Brain Axis

      2024, The Gut-Brain Axis, Second Edition
    View all citing articles on Scopus
    View full text