488 Agricultural Gazette of N.S.W. [July 2, 1920. 



bacteria which cause alkalinity in litmus milk, Bad. alcaligenes was most 

 numerous. . Others, both spherical and rod forms, were considered inert , 

 causing no apparent change in litmus milk or gelatin in ten days. 



Sample C'2 — Cream immediately after Pasteurising. — The cream had been 

 neutralised to 0*25 per cent, acidity with lime and pasteurised by means of 

 the holding system, where the cream was raised to 145 deg. Fah.,and held at 

 that temperature for twenty minutes. The sample for plating was collected 

 by means of a sterile pipette direct from the vat before the cooling process 

 began. From the plates, 1 c.c. of the cream contained • 500 bacteria ; of 

 these 490 were gram positive bacteria, which slowly coagulated litmus milk 

 with production of acid, and ten of a sporing bacillus of the B. subtilis type. 



Sample C3 — Cream imniediateli/ prior to Churning. — The pasteurised 

 cruam was cooled to 55 deg, Fah., and allowed to remain in the pasteurising 

 A'at twenty hours (overnight). The lid of the vat was kept closed, and no 

 "starter" was aHded. The sample for plating was collected by means of a 

 sterile pipette direct from the bulk in the vat. From the plates, 1 c.c. of 

 cream contained 13,400 bacteria. Of these, 1,900 were £act. lactis acidi, or 

 desirable lactose fermenters, 3,800 were streptococci, and 7,500 (including 

 spore-forming organisms of the B. subtilis type, Sarcinai and Cladothrix sp.) 

 were able to liquefy gelatin. One hundred and fifty were bacteria able to 

 produce alkalinity in milk, and fifty were chromogenic micrococci, classified 

 as inert, having caused no apparent change in litmus milk or gelatin in ten 

 days. 



Sample Ci — Butter in the Box ajter Packing. — The cream from the pas- 

 teurising and holding vat was gravitated along a fluming into the churn in 

 another room in the factory. The cream was churned in the Simplex churn. 

 The sample for plating was collected by means of a sterile instrument from 

 the near surface butter as packed in the box ready for market. From the 

 plates 1 gram of butter contained 750,000 micro-organisms. Of these, 90,000 

 (including varieties of the proteus group, Bact. fluorescens, spore-foi-niing 

 organisms, Sarcince and Bact. prodiyiostis) were gelatin liquefiers, or were 

 able to digest the casein of milk, and 614,000 were bacteria which, when 

 inoculated into litmus milk, produced acid or caused an acid coagulum. Of 

 these lactose fermenters, 500,000 were Bact. lactis acidi ; 60,000 were 

 streptococci, while the remainder of this type were varieties of micrococci, 

 some being chromogenic. Of the 4,000 organisms of the coliform group, two 

 members were isolated, viz., Bact. coli commuim and Bact. lactis aerogcnes. 

 Of the remainder, 25,000 were bacteria able to cause milk to become alkaline ; 

 10,000 were considered as inert, having made no a})parent change in gelatin 

 or litmus milk after ten days ; 5,000 were yeasts, and the 2,000 moulds were 

 species of Penicillium, Fusarium, and Cladosporium. 



Sample Co — Butter-wash Water. — The source of this supply was a well about 

 30 feet deep. This same water was also used to fiow over the condenser tower 

 and was then allowed to fiow back into the well. Samples for plating were 

 collected into sterile vessels from the tap in the churn room and also direct 

 fi'om the well. 



