Dairyland Food Laboratories, Inc.

[1984] APO 8

In the Matter of the Patents Act

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In the Matter of Patent Application No. 55177/80 in the Name of DAIRYLAND FOOD LABORATORIES, INC.

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In the Matter of Examiner's Objection thereto.

DECISION OF A SUPERVISING EXAMINER
         This matter concerns an application for a patent entitled "PHAGE DETECTION" lodged on 4 February 1980.  The application is made as a Convention application claiming priority from a United States basic application dated 21 February 1979.  Despite proposed amendments, the examiner, in the most recent report under section 48 dated 19 October 1983, has maintained an objection that the application is in respect of an invention that is not novel.  In earlier objections the examiner had taken the objection under the head of the invention not being a "manner of new manufacture".  The applicant requested a hearing which took place in Canberra on 6 June 1984 with Mr W.L. Thomson, Patent Attorney, acting on behalf of Clement Hack & Co., representing the applicant.
         The specification begins with a general discussion of the background to the invention:

"Production of cheese today is a big business involving the processing of large quantitites of milk every day.  In order to attain the desired production level it is necessary that the milk clot in a specific period of time.  Before clotting can occur there must be lactic acid production.  Lactic acid is produced by the action of starter cultures which are lactic acid bacteria which both produce the lactic acid and provide enzyme systems for flavor development during curing.  Failure to produce enough lactic acid within the time schedule results in economic loss either through dumping the vat full of milk or by degradation of the cheese quality.

The description then goes on to explain that the starter cultures are blends of genetically distinct strains or subclasses or organisms primarily within two classes of lactic acid producing bacteria, including Streptococcus cremoris and Streptococcus lactis.
         It further explains that all culture strains are subject to attack by bacteriophages.  These are bacterial viruses which can attack bacterial cells, multiply within the bacterial cell, and ultimately destroy it.  These bacterial viruses are also genetically distinct and this enables the viruses to differentiate between various strains of starter organisms ‑ thus certain viruses will attack only particular strains of S. cremoris and S. lactis.
         The specification then goes on to discuss the prior art methods used to overcome the problem of phage attack:

"Phage is always present.  Obviously a starter culture must be resistant to the phage in order to function properly.  A given blend which is today resistant cannot be used continuously, however, since the phage continuously undergoes genetic changes and culture strains that were not susceptible can become susceptible as new viruses develop against them.  Successful starter culture selection becomes a matter of staying ahead of the change in the phage in the plant.  Current methods of guarding against failure involve use of a rotation of blends of strains.  The cheesemaker uses a number of different blends on different days.  The blends are purchased from suppliers.  The relationship between the strains in a blend has usually been determined by experimental methods and by trial and error so the phage produced (built up) against one strain or blend used one day will not attack the blend (or strains therein) used on the following day or the day thereafter rotation."

It then sets out the problems with the prior art:

"the basis is trial and error and there is no assurance of success....and in practice the rotation system is only about 96% successful.  In a large cheese plant 4% is a very significant loss.

A further factor to be considered is the effect of slight loss of starter culture efficiency due to phage attack on one or two of the strains sufficient to lower lactic acid production but still passable (as opposed to dumping the milk).  This lowers the cheese quality and the change in acid (pH) could necessitate changes in the processing of the whey (a by‑product) causing economic loss."

The specification acknowledges that there are known tests for determining phage susceptibility, namely:

"The M17 agar plate method (the Australian Journal of Dairy Technology, June 1977, pp 63‑64) is used in certain laboratories but is generally regarded as requiring too much skill and experience for the cheese factory.  A simpler test involves the use of Bromcresol Purple (BCP) Milk in which the direct acidification of milk is wholly or partially inhibited by phage so that after incubating the resistant (usable) culture has turned yellow while the inhibited (not usable) culture is blue or green.  Neither the BCP method nor the M17 agar plate method has been adopted for use in the factory."

The object of the invention is said to be: "to allow the cheesemaker to choose his starter culture on the basis of the phage environment in his plant at any particular time".
         It is convenient at this point to set out proposed claim 1 and claim 10, the two independent claims.  They read as follows:

"1.A method for selecting a cheese starter culture resistant to the bacteriophage currently present in a cheese factory comprising the steps of,

preparing a multiplicity of test samples of starter cultures differing one from another and corresponding to the cultures available to the cheesemaker, each sample being in a sterile nutrient medium to which has been added a pH indicator dye which changes color in response to acid production in the curd forming process,

adding to each test sample an inoculant containing phage then present in the cheese factory;

incubating the test samples for a period of time sufficient for acid production and curd formation,

determining which of the incubated test samples has changed color indicative of acid production and has developed satisfactory curd to thereby indicate resistance to the phage present in the inoculant,

and selecting for use a starter culture in production of cheese at least one phage resistant culture from those determined satisfactory in the preceding step."

and

"10.Apparatus for testing cheese starter cultures for resistance to the bacteriophage present in a cheese factory, comprising tray means having a multiplicity of sealed test tubes,

each test tube containing a dye, a culture medium and a culture different from the other cultures,

each sealed test tube being designed for introduction of an inoculant,

said dye being a pH indicator dye which changes color in response to lactic acid development by reason of culture growth in the medium after the medium has been inoculated with a solution containing phage present in the factory and then incubated,

lack of color change in a culture indicating phage susceptibility of the culture and the desired color change indicating phage resistance of the culture whereby a usable culture may be selected from those exhibiting the desired color change."

Turning first to claim 10, this claim is directed to an "apparatus" which is capable of being used to test the bacteriophage resistance of cheese starter cultures.  The apparatus is made up of a "tray means" and a "multiplicity" of sealed test tubes.  I understand the "tray means" to include any device used to support test tubes, for example, the test tube racks commonly used in any laboratory.  The number of test tubes in the apparatus is defined by the adjective "multiplicity" ‑ thus the apparatus contains more than one test tube. The test tubes in the apparatus are sealed and are "designed for introduction of an inoculant".  The purpose of this sealing is not defined in the claim, however from a reading of the description it would appear that the purpose of the seal is to maintain sterile conditions.  A thin film seal is described however it seems to me that the claim also includes the use of a rubber stopper, for example.
         Each test tube in the apparatus is defined as containing a dye, a culture medium and a culture different from the other cultures.  The dye is defined as being a pH indicator dye which changes color in response to lactic acid development by reason of culture growth in the medium after the medium has been inoculated with a solution containing phage present in the laboratory and then incubated.  The preferred dye described in the specification is bromocresol purple (BCP), however other dyes are described as being suitable such as methylene blue or resazurin dye.  The sterile culture medium described in the specification is, unsurprisingly, sterile milk.  The "culture" referred to in claim 10 is presumably intended to be the starter culture, although the claim does not indicate this.
         So what is defined in claim 10 is essentially a collection of two or more sealed test tubes and a tray means.  Each test tube contains a culture medium, an indicator dye, and a culture.  No test tube in the "apparatus" contains the same culture as that contained in any other test tube in the "apparatus".
         The benefit of this apparatus is said to be the greater accuracy in determining the suitability of a starter culture when compared to the prior art rotation method.  It is asserted that there is an improvement from 96% success rate with the prior art method to 99.94% with the method of the present invention.
         The examiner's objection as at the last adverse report reads as follows:

"The invention as defined by claim (10) is not novel in the light of common general knowledge in the field of food microbiology.

The claim defines a set of sealed test‑tubes containing pH indicator dye, culture media, and cultures which are genetically distinct from tube to tube, and means for inoculation of the tubes.

The claim is thus a very general claim to a test kit.  It is submitted that the arranging of distinct cultures with dye/media in a row of test‑tubes would occur to the skilled food microbiologist.

The dye is known (admitted prior art on page 3 lines 12‑13, and chemical abstract reference, as well as applicant's comments in attorney's reply of 29.9.83).  The arrangement of test tube's or such like for use in microbiological assays is also known (e.g. US patent 3713985, in describing a particular device, outlines the common knowledge of biological testing arrangement; see applicant's comments in reply of 29.9.83).

No ingenuity is involved in bringing together the test‑tubes for simultaneous testing of cheese‑starter cultures.  The merit of a single test tube with dye/media and a multiple rack of such test tubes for testing phages is the same.  This applies despite the fact that the multiple rack of such test tubes might be more convenient and neater for use by the cheese factory microbiologist.  The arrangement can readily be devised by the application of common general knowledge.  It is mere saving of time, trouble and expense to treat all cultures simultaneously.  This simultaneous testing involves no special expedient to secure any greater efficcy of treatment for each culture.

Claim (1) is not novel for reasons similar to those outlined by objection (9) above."

In this report the examiner refers to the attorney's response to the previous adverse report.  The relevant part of the response reads as follows:

"We still do not agree with the Examiner as to rejection of the apparatus claims.  One example that he gave us is a test kit where, in effect, you build it yourself.  You get all the various components and you can package it and use it.  What we are claiming is a kit in which the starter culture in each test tube is different from every other starter culture so as to enable a test to be performed.  The test itself, i.e., with the indicator dye is old per se, but not when done simultaneously with many other starter cultures.  To our knowledge, nobody has run simultaneous tests on many starter cultures to determine which are satisfactory for use under the present phage conditions in the cheese factory.  Similarly, nobody has packaged a test kit to permit that test to be run simply without any technical skills required of the operator.  Cheesemakers are not noted for their scientific ability.  The present test is so simple that the cheesemaker can be a person with very little education and still determine, with heretofore unobtained accuracy, which starter culture will be satisfactory.  The Examiner has tried to meet the apparatus claims by showing us apparatus parts are old and that the dye test itself is old.  We don't argue with that.  On the other hand, we say that nobody has heretofore assembled a prepackaged test kit permitting the simultaneous testing to be done."

It seems clear from the attorney's response that the above argument is provided by the applicant itself.
         Mr Thomson, at the hearing, did not resile from the admission made by the applicant that the test with the indicator dye is old per se.  The examiner has cited an extract from Chemical Abstracts, Vol. 51, No. 21, 10 November 1957 column 17003.  The abstract reads as follows:

The suitability of several tests for detecting bacteriophage action is described with regard to cheese starter cultures composed of a no. of strains.  Strain dominance is considered to be of importance in defg. the efficacy of any particular phage detection test.  A modified methylene blue reduction test is described which gives good results as a means of detecting phage active against multistrain cheese starters.  The test is simple, requires little equipment, and gives results in a short time.  For creameries the test is useful in making "on the spot" detns. of the phage relations of the various starters."

That bacteriophage can create problems with starter cultures appears to have been known from a very early date, for example, the publication "A Dictionary of Dairying" by J.G. Davis, second edition, available in the Patent Office Library on 4 April 1955, discusses the matter.  The latter reference contains an extensive discussion on starters as well as a separate paragraph on slowness of starters due to bacteriophage action (page 983).  Under the "Cheese" treading at page 171 it indicates:

"Acidity is one of the major factors in cheesemaking, both in actual clotting of the milk and in mellowing of the curd.  A slight development of acidity is necessary in order to permit the formation of a workable rennet clot.  Originally cheesemakers relied on the natural developed acidity of the milk, as in practice milk is always contaminated with acid-­producing bacteria, but in the last thirty years the use of lactic milk cultures of lactic steptococci known as "starters" has become practically universal ....  Failure of milk and starter to develop the acidity leads to most serious troubles.  Not only is the whole cheesemaking timetable upset, but "slow starter", as the fault is called, frequently results in weak curd, high moisture, and taints in the cheese.  When only one or two vats in the factory are affected the trouble is probably due to the milk .....  If all the vats are affected, it is obvious that the starter itself is at fault and the reason is almost certainly bacteriophage .....  It is now accepted that the real factor controlling curd behaviour is pH or hydrogen ion concentration.  This factor can be measured by coloured indicators or electrical pH meters."

If I turn to the publication referred to by the specification at page 3, that is, the Australian Journal of Dairy Technology June 1977, pp 63‑64, I find that it indicates that there are two methods available for the detection of bacteriophage activity; inhibition of lactic acid production by the starter in sterile reconstituted skim milk, and the plaque assay.  The latter assay is the M17 method referred to in the present specification.  The example of the "inhibitor method" given the Journal is as follows:

"Samples suspected of containing bacteriophages should be filtered using a Seitz or membrane filter (0.4  m pore size) that will trap bacteria but allow bacteriophage to pass through and tested promptly as follows.  A series of tubes containing 10 ml of sterile reconstituted skim milk are inoculated with 1% (v/v) of the appropriate starter organism.  (Grow all starters in sterile skim milk at 25oC until the milk has just clotted and either use immediately or dilute 1:10  in sterile skim milk and store below 5oC.)  Add 0.1‑ml amounts of the samples suspected of containing bacteriophages to these tubes and incubate as described above.  After incubation, measure the pH of the milk in each tube and compare the results with those of the control tubes where no bacteriophage was added."

It is interesting to note that with the M17 method discussed in the Journal the instruction is given that one plate is used for each starter strain "currently in your rotation".
         All the above corroborates the applicant's admission that the dye test itself is known.  As the applicant admits, the parts of apparatus claim 10 are old and the dye test itself is old.  The argument the applicant relies on in support of its contention that the apparatus defined in the claims is patentable is that "nobody has heretofore assembled a prepackaged test kit permitting the simultaneous testing to be done".  Furthermore it is asserted that to the applicant's knowledge, nobody has run simultaneous tests on many starter cultures to determine which are satisfactory for use under the present phage conditions in a cheese factory.
         I agree that it would be more convenient to have a prepackaged kit, it saves time in not having to prepare the media etc. from scratch.  However if the relevant person were supplied with an apparatus according to claim 10 ‑ a test tube tray and at least two test tubes containing culture media, an indicator, and a different culture in each sealed tube ‑ there is nothing to stop that person from carrying out the indicator test on a single starting culture rather than simultaneously testing a number of cultures.  Furthermore there is nothing to stop anyone from using it outside the factory environment.  There is nothing in the design of the device to ensure that the use of the apparatus is in accordance with the "inventive concept" of simultaneous testing of a number of starting cultures.
         Claim 10 defines a set of integers which are admittedly old.  I can find no working inter‑relationship or potential working inter‑relationship between the components.  Furthermore, I can see no evidence of any problem encountered or overcome in associating the sealed test tubes side by side.
         As to the other claims relating to the apparatus I do not at this point, consider them to contain anything that would confer novelty on the apparatus claim.  Appended claim 11 specifies that the culture media is sterile non‑fat milk, however this is disclosed in the Australian Journal of Dairy Technology 1977 (referred to in the present specification).  Claim 12 specifies that the medium and the test culture are freeze dried and are reconstituted by later addition of sterile water.  However, it is common knowledge that freeze dried culture media are suitable for this purpose.
         Appended claims 13, 14 and 15 specify the nature of the starter cultures in each sealed tube, however, this does not compel the user to use these tubes in a simultaneous test.  Similarly I do not consider that appended claims 16 and 17 contain anything that would confer novelty on a claim to the apparatus.
         Similar comments apply to method claim 1.  What this claim defines is a mere multiplicity of treatment, that is, rather than carrying out the known dye test on one starter culture, the test is carried out on a number of starter cultures and includes the selection of just one of the satisfactory cultures.  I consider this desideratum to be neither a manner of new manufacture nor novel having regard to what is known in the art.  Mr Thomson did not present arguments in relation to the other claims relating to the method and because I have no information whether a novel aspect is included in any of these claims, I make no conclusion on these claims.

         Mr Thomson did indicate that the applicant was willing to amend the claims.
         Claim 1 of the proposed claims reads as follows:

"A packaged test kit comprising a multiplicity of sealed receptacles, each receptacle containing a pH indicator dye, a sterile culture medium and a cheese starter culture, the starter culture in each receptacle being different from the starter culture in any one of the other receptacles, the seal of each receptacle enabling the introduction of an inoculant containing phage, and the pH indicator dye being responsive, by changing colour, to lactic acid development by reason of culture growth in the medium after the introduction of the inoculant.

It will be noted that there are some differences between this claim and claim 10.  Notably the apparatus is now called a "package test kit"; the kit no longer requires the presence of the tray means' and the culture is now defined as a starter culture.  The words "packaged test kit" provide no restriction other than requiring that the test tubes be packaged in some way, for example, by being enclosed in a paper bag or by being held together with an elastic band.  I do not consider that changes the basic characteristics of the apparatus claim, and it is therefore still not novel.
         As there may be patentable subject matter in the specification I direct the applicant to lodge a statement of amendments to my satisfaction within the time remaining for acceptance.

P.A. KILBORN
Supervising Examiner of Patents