974 
Journal of Agricultural Research 
Vol. XXX, No 10 
no pronounced odors, but they bring 
about a marked increase in acidity. The 
lactobacilli produce both a sour odor 
and an increase in acidity. These 
organisms, isolated from sour oysters, 
have been found to ferment dextrose, 
lactose, sucrose, maltose, arabinose, 
and trehalose. Some yeasts and yeast¬ 
like forms produce no odor in oysters 
and oyster infusion medium in pure 
culture. Some of the yeasts isolated 
do not ferment any of the carbohy¬ 
drates and apparently play no part in 
the spoilage of oysters. The yeasts in¬ 
cluded in Table II, however, produce 
sour, yeasty, or aromatic odors, as 
well as an increase in acidity in the 
oysters. Owing to the difficulties in 
such work, no attempt has been made 
to identify the yeasts beyond an 
examination for ascospore formation. 
From the observations made it is 
apparent that most of the yeasts 
belong to the group of Torulae. 
spoilage. Others, which were present 
at the beginning of the experiment, 
either disappeared or were overgrown 
by other groups. The yeasts were 
usually obtained during the late stages 
of spoilage. Although the organisms 
in this table apparently have no effect 
on oysters in pure culture, it is not 
improbable that under natural condi¬ 
tions they supplement the activities of 
the other organisms present in bringing 
about decomposition. 
In studying oysters from polluted 
and unpolluted sources, Fuller (/+) 
found that the bacterial flora of the 
oysters was almost identical with that 
of the sea water from which they were 
taken. His work and the earlier works 
of Wood (16, p. 759-764), Foote (3), 
and Sabatier, Ducamp, and Petit (10) 
are in close agreement with the findings 
of the investigation reported here. 
The identity of the flora of the oysters 
and of the sea water is often destroyed 
Table Hi .—Organisms producing only slight 11 off' 1 odors or no ohjectionahle odors 
in oysters or oyster infusion medium 
Culture 
(CS) 
Number 
of times 
isolated 
Stage of spoilage when isolated 
Type resembled 
2M. 
1H_ 
3M_ 
6 E_. 
15L. 
17c_ 
lAis 
2 K_ 
45 
2 
26 
2 
1 
7 
1 
12 
Present throughout whole period of spoil¬ 
age. 
_do_ 
_do_ 
Isolated during early stages of spoilage_ 
Isolated during late stage of spoilage_ 
Present throughout whole period of spoil¬ 
age. 
Isolated during late stage of spoilage_ 
Present throughout whole period of spoil- 
Achromobacter raveneli (Chester). 
Achromobacter superficialis (Jordan). 
Achromobacter inunctum (Pohl). 
Achromobacter tiogense (Wright). 
Achromobacter stoloniferum (Pohl). 
Achromobacter solitarium (Ravenel). 
Eberthella sp. (Castellani and Cham¬ 
bers). 
Eberthella leporis (Sternberg) 
3R-. 
3A._. 
7C__ 
9A__. 
14A 4 
17P-. 
3B__. 
age. 
2 Isolated during late stage of spoilage. 
2 
1 
3 
1 
1 
14 
Isolated during early stage of spoilage_ 
_do_ 
---do_ 
_do_ 
_do_ 
Present throughout whole period of spoil- 
Flavobacterium aurantinum (Ham¬ 
mer) . 
Flavobacterium sp. 
Flavobacterium annulatum (Wright). 
Flavobacterium sulfureum (Zettnow). 
Flavobacterium rigensis (Bazarewski). 
Flavobacterium deciduosum (Wright). 
Micrococcus candicans (Fliiggc). 
5A9— 
IOA12. 
17Ai_ 
1U- 
IX-_ 
19F- 
19A 2 . 
21D_ 
NYs. 
19E— 
13 A 2 . 
age. 
1 Isolated during late stage of spoilage.. 
2 Isolated during early stage of spoilage 
1 _do_ 
2 Isolated during late stages of spoilage. 
1 _do_ 
1 _do_ 
1 Isolated during late stage of spoilage.. 
1 _do_ 
5 _do_ 
1 _do_ 
1 Isolated during early stage of spoilage 
Staphylococcus citreus (Passet). 
Micrococcus subflavescens. 
Micrococcus freudenreichii (Guille- 
beau). 
Pink yeast. 
Do. 
Do. 
Yeasts. 
Do. 
Do. 
Yeastlike fungus. 
Actinomyces. 
The organisms in Table JJ.1, which 
were isolated from oysters and yet 
have no pronounced effect when inocu¬ 
lated into oysters or oyster infusion 
medium, are for the most part ordinary 
nonspore-forming water and soil bac¬ 
teria. Some of these organisms per¬ 
sisted throughout the whole period of 
by handling under unsanitary condi¬ 
tions. 5 The organisms which have been 
found in oysters, some of which bring 
about spoilage, are common water and 
soil organisms. This accords with the 
conclusions reached regarding the source 
and characteristics of the bacteria 
causing decomposition in salmon. 5 
5 Personal communication from P. B. Parsons, Bureau of Chemistry. 
