COMMISSIONER'S DECISION
OBVIOUSNESS: Yeast Production
A process to produce a particular yeast by cultivation on a nutrient
medium in the absence of added growth factors was held unpatentable
over prior art.
FINAL ACTION: Affirmed
This decision deals with a request for review by the Commissioner
of Patents of the Examiner's Final Action dated November 8, 1973,
on application 056,232 (Class 195-54). The application was filed on
July 4, 1969, in the name of Jozef T. DeLey et al, and is entitled
"Process For Growing The Yeast,Candida Guilliermondii, On Petroleum
Hydrocarbons." The Patent Appeal Board conducted a Hearing on
May 7, 1975, at which Mr. R. Fuller represented the applicant.
The present claims relate to the production of a particular yeast,
Candida guilliermondii, by cultivation on a hydrocarbon-containing
nutrient medium in the absence of added growth factors. The recovered
yeast is useful as a food supplement.
In the Final Action the examiner refused claims 1 to 10 on the grounds
that they fail to show invention over the following references:
Chemical Abstracts
Volume 66 113256u 1967
Canadian Patents
670,301 Sept. 10, 1963 Cl. 195-35
788,976 July 2, 1968 Cl. 195-64.1
United States Patent
3,268,419 Aug. 23, 1966 Cl. 195-82
In that action the examiner stated (in part):
The Chemical Abstracts reference discloses the cultivation
of Candida guilliermondii on an aqueous medium containing hydro-
carbons, a nitrogen source and inorganic salts to yield a cell
product comprising 50% protein. The cited patents in turn
show that such a medium can be used for the aerobic cultivation
not only of Candida yeasts but also of other yeast genera and
hydrocarbon-assimilating, bacteria within the pH and
temperature limits claimed by the applicant. Moreover the
form of paraffinic hydrocarbon can vary over a wide range to
include kerosines, gas oils, middle distillate fractions and wa~
Although his original claims did not specify this feature, appli-
cant now contends, in his letter of March 27, 1973, that the
proviso relating to the absence of added growth factors in the
present claims is neither taught nor suggested in the cited refer-
ence and that on this account these claims are patentable.
However it is stated in the disclosure of each of the applied
patents that: "the growth of the yeasts (or microorganism)
used is favoured by the addition to the culture medium of a very
small proportion of extract of yeast or more generally of vitamins
of group B and/or biotin". The implication of this statement is
not that the presence of growth factors is an absolutely vital
requirement but that these substances may improve the rate of growth
of the microorganism according to the conditions chosen. It is
therefore clear that the exclusion of the said growth factors
does not in itself represent a patentable improvement over the
prior art nor, as shown above, are the claims patentably
distinguishable in other respects from the teachings of the cited
references.
In the response dated Feb. 7, 1974, to the Final Action the applicant
stated (in part):
...
Applicants wish to point out that in rejecting claims 1 to 10
the Examiner appears to be relying on a combination of two or more
references. It is believed that such a combination of references is
only permissible under Canadian practice under very special circum-
stances when an obviousness rejection is being made. Thus when
making such an obviousness rejection the references can only be
combined if they relate to the same problem and it can be said that
at least one of them represents what is common general knowledge in
the art. It is not considered that these requirements are met in
the present case. The Examiner also alleges that the method for
culturing Candida guilliermondii on paraffinic hydrocarbons and an
aqueous nutrient medium in the absence of added growth factor does
not represent a patentable improvement over the prior art.
Applicants do not agree with such a statement as they have pre-
viously argued....
...
Although the three Champagnat et al patents are directed to the
metabolism of yeast on a petroleum substrate and provide more
detailed teachings than in the Chemical Abstracts citation, none
of these three patents are directed to the growth of Candida
guilliermondii on paraffinic hydrocarbons as is the process
being claimed herein. These patents are directed principally
to Candida lipolytica although other species of Candida yeasts
and other hydrocarbon-utilizing microorganisms are disclosed.
However the species of Candida being claimed herein is nowhere
disclosed nor demonstrated in the three patents.
Not all species of Candida yeasts will grow on hydrocarbons as
is clearly shown in the Klug et al reference cited in the U.S.
prosecution of this application. Klug et al, a copy of which
is attached hereto, presents the growth response of over
30 species of Candida and demonstrates that many of these species
are incapable of assimilating paraffinic hydrocarbons. Further,
the present application demonstrates in Example I (pages 6-8)
that only 6 of 26 Candida species grew well on a petroleum substrate.
Since Klug et al and applicant's application show that not
all Candida species have the ability to metabolize paraffinic
hydrocarbons and the Champagnat et al patents are directed to
Candida species other than C.guilliermondii, one skilled in
the art could not predict the applicability of the Champagnat
et al disclosures to C. guilliermondii short of actual laboratory
testing. The predicability of applicant' process from these
references is uncertain.
Further, the Champagnat et al references are deficient for another
reason. In the process being claimed herein, a utilizable source
of carbon, a utilizable source of nitrogen (usually ammoniacal
nitrogen) and certain inorganic salts are disclosed as being
necessary to promote the growth of Candida guilliermondii.
Although the Champagnat et al patents disclose the necessity for
a source of carbon and inorganic nutrition sources, there is no
disclosure that a utilizable source of nitrogen is necessary.
While the nutrient medium employed by Champagnat et al in the
examples of these patents did in fact contain nitrogen-containing
salts, Champagnat et al failed to recognize that this nitrogen
source was essential since none of the claims of those patents
are directed to this feature. Applicant's claims require a source
of nitrogen in the nutrient medium.
The text of the chemical abstract reads:
Isolation and growth characteristics of C. guilliermondii on ali-
phatic hydrocarbons was investigated. The yeast was cultivated
on the following medium: Mepasin (A kerosine fraction) 10 ml,
NH4Cl 2,KH2PO4 4.5,M g So4 0.2 and NaCl 0.2 g in 1 1.H20. Two
hundred ml of this medium in a 500 ml flask was inoculated and
incubated in shaken culture at 30·: A dry yeast product (0.7g)
contg. about 50% protein was obtained in 5 hrs. The optimal concn.
a no. of sat. and unsatd. paraffins was studied including C12
to C22. The respiratory coeff, and the riboflavino content of the
product are given.
The Champagnat patents show the need to provide a supply of oxygen for
the growth of Candida yeasts and other micro-organisms on hydra carbons,
and to control the pH of the medium to between 3 to 6.
The application is concerned with the cultivation of a yeast, Candida
Guilliermondii. Claim 1 reads:
A process for the production of yeast which comprises
aerobically culturing Candida guilliermondii on an
aqueous nutrient medium containing a nitrogen source
and inorganic nutrition sources in the presence of a
feedstock containing a mixture of paraffinic petroleum
hydrocarbons as a carbon source and in the absence of
added growth factors wherein the pH is controlled be-
tween about four and six and the temperature is maintained
between 15 and 30.degree.C and recovering the yeast produced.
The question which the Board must consider is whether the applicant
had made a patentable advance in the art.
It is noted that the detailed procedure for cultivating edible micro-
organisms on hydrocarbons, with regard to other nutrients such as nitro-
gen sources, mineral salts, trace elements and pH and temperature
conditions, is set forth in the cited patents, These are applicable not
only to Candida and other yeasts but also to hydrocarbon - assimilating
moulds and bacteria and are essentially the same as in the applicant's
process. It is also clear from the above mentioned patents that Candida
species require oxygen in order to metabolize hydrocarbons. We do not
believe that there is anything unexpected in the finding the C.
guilliermondii shows a similar oxygen requirement.
It is observed that the absence of added growth factors, a feature
where the applicant now alleges is inventive, was not specified in the
claims prior to his amendment of March 27, 1973. It is stated in the
disclosure of each of the applied patents that: "...the growth of the
yeasts (or microorganism) used is favoured by the addition to the
culture medium of a very small proportion of extract of yeast or more
generally of vitamins of group B and/or biotin." Surely the implication
of this statement is not that the presence of growth factory is an
absolutely vital requirement, but that these substances may improve the
rate growth of the microorganism according to the conditions chosen.
The Chemical Abstracts reference specifically discloses a nutrient medium
containing an ammonium salt. The cited patents similarly reveal the
need for a nitrogen source and since the microorganism obviously requires
nitrogen is order to synthesize protein, it is self-evident that this element
must be supplied in the medium together with other conventional nutrients.
In our view, the process which the applicant is claiming amounts to nothing
more than the use of the conventional procedure for cultivating hydrocarbon -
assimilating microorganisms in general for the production of a particular
yeast which is known to possess this same ability to utilize hydrocarbons.
Apart from the fact that the Chemical Abstracts reference makes no mention
of the addition of growth factors, it is clear that, in the processes of the
cited patents, the provision of these substances is optional rather than
mandatory and their exclusion does not therefore represent a patentable
advance in the art.
The applicant argues that his aerobically culturing is important. The
chemical abstract is basically performing the same step "...inoculated and
incubated in shaken culture at 30.degree....."
Upon reviewing all the evidence presented to us, we have concluded that the
most that has been done by the applicant is mere verification. We cannot
see that there has been any exercise of the inventive faculty. It is
settled law that minor experimentation does not amount to invention. On this
point we refer to British Thomson-Houston v. Charlesworth (1925) 42 R.P.C. 180,
Sharp & Dohme v. Boots Pure Drug (1927) 44 R.P.C. 367 at 402 and (1928)
45 RPC 153 at 172 & ff, and quote from 44 RPC 402:
If it be that, having regard to what the world knows in the art,
the making of the body, if it be a body in a patent, is a
matter of routine, is a matter which the ordinary tools of the
chemist will enable him to obtain, or is a matter which will be
obtained in fact, if you follow the anticipatory directions
contained in the document, then there may be no subject-matter
in the patent, although the contents of it do not
appear in the way of anticipation.
We recommend that the application be refused.
J.F. Hughes,
Assistant Chairman,
Patent Appeal Board.
1 concur with the findings of the Patent Appeal Board and refuse
to grant a patent. The applicant has six months within which to
appeal this decision under the provision of Section 44 of the
Patent Act.
Decision accordingly,
A.M. Laidlaw,
Commissioner of Patents.
Dated at Hull, Quebec
this 24th.day of July,
1975.
Agent for Applicant
Messrs, Smart & Biggar
70 Gloucester St.,
Ottawa, Ontario