Technology and safety assessment for lactic acid bacteria isolated from traditional Bulgarian fermented meat product "lukanka"

Abstract The present work discusses the technological and new selection criteria that should be included for selecting lactic acid bacteria for production of fermented meat. Lactic acid bacteria isolated from Bulgarian traditional fermented "lulanka" salami was studied regarding some positive technological parameters (growth at different temperature, pH, and proteolytic activity). The presence of genes related to the virulence factors, production of biogenic amines, and vancomycin resistance were presented in low frequency in the studied lactic acid bacteria. On the other hand, production of antimicrobial peptides and high spread of bacteriocin genes were broadly presented. Very strong activity against L. monocytogenes was detected in some of the studied lactic acid bacteria. In addition, the studied strains did not present any antimicrobial activity against tested closely related bacteria such as Lactobacillus spp., Lactococcus spp., Enterococcus spp. or Pediococcus spp. To our knowledge this is the first study on the safety and antimicrobial properties of lactic acid bacteria isolated from Bulgarian lukanka obtained by spontaneous fermentation.

Isolation of compound and CNS depressant activities of Mikania scandens Willd with special emphasis to brain biogenic amines in mice.

Mikania scandens, a twining herb that grows as a weed in India and Bangladesh is used as vegetables and is a good source of vitamin A, C, B complex, mikanin, sesquiterpenes, betasitosterin, stigmasterol and friedelin. The present communication reports CNS depressant activities with special emphasis to brain biogenic amines in mice. Ethanol extract of leaves of M. scandens (EEMS) was prepared by Soxhalation and analyzed chemically. EEMS potentiated sleeping time induced by pentobarbitone, diazepam and meprobamate and showed significant reduction in the number of writhes and stretches. EEMS caused significant protection against pentylene tetrazole-induced convulsion and increased catecholamines and brain amino acids level significantly. Results showed that EEMS produced good CNS depressant effects in mice.

The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria

The influences of fish infusion decarboxylase broth (IDB) on biogenic amines (BA) formation by lactic acid bacteria (LAB) were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream) IDB. The result of the study showed that significant differences in ammonia (AMN) and BA production were observed among the LAB strains in fish IDB (p < 0.05). The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM), dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L) and mackerel (100.84 mg/L) IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L) in sardine IDB.

Effect of intracerebroventricular methotrexate on brain amines.

Intrathecal methotrexate in children with leukemia is known to cause seizures, dementia, leukoencephalopathy and cognitive dysfunction. To investigate the role of brain amines in cognitive dysfunction, male Wistar rats were given multiple intracerebroventricular injections of methotrexate. Our earlier studies in this regard revealed disruption of brain monoamines in hippocampus with severe cytotoxic effect on CA4 hippocampal neurons. Further extending this study, the levels of brain monoamines in frontal cortex, hypothalamus and brainstem were estimated by HPLC method and histopathological study of the frontal cortex. The concentration of all three-brain amine (norepinephrine, dopamine and serotonin) levels was reduced in 2 mg/kg dose of methotrexate in frontal cortex and brain stem. Hypothalamus did not show any significant change in brain monoamine levels. No structural changes in the frontal cortex neurons were observed. Disruption of brain monoamines has been proposed as a cause of brain dysfunction from this chemotherapy. The outcome of the study may have therapeutic implications in the management of childhood lymphoblastic leukemia.

Interrelationship between amines level in brain regions of fish, Oreochromis mossambicus during organophosphorus stress.

Amines such as dopamine, norepinephrine and epinephrine were analysed in the brain regions of O.mossambicus exposed to quinalphos, phenthoate and their combination for 96 hr. The three types of treatments significantly (P < 0.05) altered the amines level at various intervals in the brain regions.

Effect of diethyl carbamazine on neurotransmitter amino acids, biogenic amines and certain related enzymes in Setaria digitata.

Effect of diethyl carbamazine (DEC) on the levels of neurotransmitter amino acids and on the activities of related enzymes of S. digitata have been studied. When the worms were incubated in DEC, substances known to have neurotransmitter effect were found increased except glycine. Among the amines the level of serotonin, dihydroxy phenyl alanine and epinephrine were increased and that of histamine remained the same. DEC inhibited activities of monoamine oxidase, aspartate amino transferase and alanine amino transferase and enhanced those of cathepsin and glutamate dehydrogenase. The effect of DEC on the activities of the enzymes appear to account for the increased level of amino acids and amines. Results indicate that the reversible paralysis caused by DEC is due to the accumulation of neurostimulants and associated decrease in the concentration of inhibitors.

Effect of amygdaloid kindled seizures during pregnancy on neonatal brain biogenic amines

The effects of amygdaloid kindled seizures during pregancy on the concentrations of noradrenaline (NE), dopamine (DA) and serotonin (5HT) and of their repective metabolites, 3-methoxy-4-hydroxyphenylglycol (MHPG), normetanephrine (NMN), homovanilic acid (HVA) and 5-hydroxy-indoleacetic acid (5HIAA), have been studied in the cerebral cortex, brain stem and cerebellum of rat offspring at bith. The levels of DA and NE were invreased and those of HVA and MHPG wee not modified in the cortex. The levels of DA, NE, 5HT, MHPG and 5HIAA were increased in the cerebellum. The brain stem presented a decrease in DA and 5HT levels, but increased MHPG and HVA levels. It is suggested that, in order to investigate possible changes in the biogenic amine loevels on the postnatal period, carefully planned prospective studies are needed

Studies on monoamine levels in rat myocardium in different stresses.

Albino rats were exposed to isolation, haemorrhagic, and psychic stress. The myocardial norepinephrine (NE), epinephrine (E), dopamine (DA), 5-hydroxytryptamine (5HT) and 5-hydroxy indole acetic acid (5HIAA) were quantitatively estimated at varying periods of time. The results indicate that 5HT, E, and DA are the common denominators in various types of stress and show similar qualitative changes in all the stresses studied whereas norepinephrine shows both quantitative and qualitative differences in the various stresses studied indicating thereby a differential modulatory mechanisms operating for the release of noradrenaline.

Methanol induced biogenic amine changes in discrete areas of rat brain: role of simultaneous ethanol administration.

Alteration in the steady state level of brain biogenic amines produced by methanol differ considerably in rats when compared to the effects produced by ethanol. When ethanol and methanol were administered simultaneously in identical concentration, the effects produced by methanol were much more pronounced in the presence of ethanol. This could be attributed to the delay in the metabolism of methanol as ethanol competes with methanol for alcohol dehydrogenase enzyme activity. Hence, it is presumed that the effects produced by methanol seem to be primarily due to the direct action of methanol itself and not due to metabolic end products of methanol. It is also inferred that if methanol per se is going to produce any permanent damage in the central nervous system due to abnormal neurotransmitter behaviour, they cannot be prevented by treatment with ethanol.

Influence of isolation stress on monoamine levels in discrete regions of the rat brain correlated with behaviour.

Various forms of stressful stimuli have been shown to affect brain catecholamine (CA) and indoleamine (IA) levels, although the literature contains some conflicting views. Changes in monoamine levels were also found to accompany the behavioural changes in animals. In the present study an attempt was made to correlate the behavioural changes with the monoamine level in discrete regions of rat brain after different periods of isolation stress. The results clearly indicate that not only the central norepinephrine and dopamine neurons involved in the expression of aggressive behaviour after isolation stress but also the serotoninergic neurons might take part.

Effect of voluntary retention of urine on plasma and urinary biogenic amines as well as circulatory and respiratory responses.

Stress caused by voluntary retention of urine in 25 normal healthy volunteers has been estimated by measuring the levels of biogenic amines (serotonin, catecholamine) in blood and urine. Estimations were done before and after voluntary retention of urine. Plasma and urine catecholamines and 5-HT significantly increased after retention. Simultaneously rise in BP, PR, RR were also observed. Inference has been drawn that retention of urine may induce stress.