295. The problem of bacteriophage in cheese making: Part I. Observations and investigations on slow acid production

1942 ◽  
Vol 13 (1) ◽  
pp. 58-72 ◽  
Author(s):  
E. B. Anderson ◽  
L. J. Meanwell
Keyword(s):  
Lactic Acid ◽  
New Zealand ◽  
Acid Production ◽  
Single Strain ◽  
Pasteurized Milk ◽  
Cheese Making ◽  
Source Of Infection ◽  
Sudden Failure ◽  
Probable Source ◽  
Specific Bacteriophage

That bacteriophage is the cause of much loss to the cheese-making industry of New Zealand has been shown by Whitehead(1). In New Zealand in recent years, cheese has been made almost entirely from flash-pasteurized milk with the aid of starters prepared from single-strain cultures of lactic acid streptococci (Str. cremoris). The use of such starters has been accompanied by the occasional failure of the bulk starter to clot, or, if clotted, by failure to produce the required amount of acid in the cheese vat—the latter condition being described by Whitehead as ‘pack up’. Whitehead has traced the cause of sudden failure to air-borne infection of the bulk starter by specific bacteriophage (2), the most probable source of infection being the spray from whey separators. When adequate protection from phage contamination was provided slowness in cheese making disappeared.

Starters and Bacteriophages in Lactic Acid Casein Manufacture

1975 ◽  
Vol 38 (5) ◽  
pp. 275-278 ◽  
Author(s):  
T. D. THOMAS ◽  
R. J. LOWRIE
Keyword(s):  
Lactic Acid ◽  
New Zealand ◽  
Acid Production ◽  
Continuous Selection ◽  
Streptococcus Cremoris ◽  
Selection For ◽  
The Individual ◽  
First Time ◽  
Selection Of

A controlled starter system was used for the first time in commercial lactic acid casein manufacture in New Zealand. Multiple starters of up to four components were constructed from 18 recently derived Streptococcus cremoris isolates which were not lysed by any of the phages in the collection of the New Zealand Dairy Research Institute. During the first season of casein manufacture, phages attacking 17 isolates were detected in the casein whey. Of these, 12 prevented adequate acid production by the appropriate host even at levels below 1 phage per 10 to 1000 ml in the milk before starter addition. In contrast, the first detected phages attacking the other five isolates did not significantly influence the rate of acid development; use of these starters continued until phages which eliminated acid production appeared. An alternative starter system based on the continuous selection of “phage-tolerant” cultures was investigated. Regular addition of whey, from previous manufacture, to the individual mother cultures of each component permitted long-term use of the multiple starter. This procedure of continued selection for phage-tolerant organisms has been used successfully for a complete season in a major casein factory.

301. The effect of over-ripening upon the activity of Cheddar cheese starters

1943 ◽  
Vol 13 (2) ◽  
pp. 127-135 ◽  
Author(s):  
C. K. Johns ◽  
H. L. Bérard
Keyword(s):  
New Zealand ◽  
Experimental Evidence ◽  
Cheddar Cheese ◽  
The Other ◽  
Extreme Conditions ◽  
Single Strain ◽  
Permanent Damage ◽  
Cheese Making ◽  
Other Hand

The belief that over-ripening of starters is responsible for their weakening and for slow acid development during Cheddar cheese-making has been widely held by cheese-makers for many years. Statements that over-ripening is harmful have been made by investigators in several countries(1,2,3,4), but experimental evidence in support of this view is scanty. On the other hand, Whitehead(5) in New Zealand has shown that prolonged over-ripening of single-strain starters under rather extreme conditions merely resulted in a temporary checking of their activity; between wide limits of size of inoculum and period of incubation no permanent damage was done.

F-specific bacteriophage as an indicator of human viruses in natural waters and sewage effluents in Northern New Zealand

1995 ◽  
Vol 31 (5-6) ◽  
pp. 231-234 ◽  
Author(s):  
Gillian D. Lewis
Keyword(s):  
New Zealand ◽  
Comparative Study ◽  
Marine Environment ◽  
Natural Waters ◽  
Sewage Effluents ◽  
Pathogenic Viruses ◽  
Human Viruses ◽  
Specific Bacteriophage ◽  
Beach Water

To assess the F-specific bacteriophage as an indicator of pathogenic viruses, a comparative study has been made of the occurrence of F-phage and human enteroviruses in sewage wastes and the marine environment. Although F-phage seemed in several respects to match pathogen behaviour, its low abundance in bathing beach water, uncertainty as to its source and other detection irregularities make its use as an indicator problematical.

scholarly journals Protective effect of titanium tetrafluoride and silver diamine fluoride on radiation-induced dentin caries in vitro

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Beatriz Martines de Souza ◽  
Mayara Souza Silva ◽  
Aline Silva Braga ◽  
Patrícia Sanches Kerges Bueno ◽  
Paulo Sergio da Silva Santos ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Protective Effect ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Negative Control ◽  
Titanium Tetrafluoride ◽  
Silver Diamine Fluoride ◽  
Dentin Caries ◽  
Radiation Induced

AbstractThis in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.

scholarly journals Lactic acid production ability of Lactobacillus sp. from four tropical fruits using their by-products as carbon source

Heliyon ◽  
2021 ◽  
Vol 7 (5) ◽  
pp. e07079
Author(s):  
Joel Romial Ngouénam ◽  
Chancel Hector Momo Kenfack ◽  
Edith Marius Foko Kouam ◽  
Pierre Marie Kaktcham ◽  
Rukesh Maharjan ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Carbon Source ◽  
Acid Production ◽  
Lactic Acid Production ◽  
Tropical Fruits ◽  
By Products

scholarly journals Hardening Properties of Cheeses by Latilactobacillus curvatus PD1 Isolated from Hardened Cheese-Ddukbokki Rice Cake

2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactobacillus Casei ◽  
Leuconostoc Mesenteroides ◽  
The Other ◽  
Rice Cake ◽  
Two Samples ◽  
High Protease Activity

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.

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