Microbiological Film Production J. R. SANBORN, International P a p e r Company, Glens Falls, N, Y.
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N ACCOUNT has been given elsewhere ( 2 ) of the for-
dominating flora, physical conditions at surfaces of attachmation of films and membranes from cultures of micro- ment, and the influence exerted by the nonfibrous raw maorganisms. The investigation was undertaken follow- terials used in paper manufacture. I n contrast to the undeing certain observations made during a study of ropiness in sirable and uneconomic aspects of slime development, it is cultures of marine bacteria. The stringy growths were drawn quite possible that the activities of certain members of the out into fine continuous filaments which, after treatment in a group may be employed to advantage. Using special met,hods coagulating bath, possessed cohesiveness and pliability. The of cultivation, many of the causal species produce substances cultures used were those of Achromobacter pellucidum Harrison possessing desirable physical and chemical properties. For and Achromobacter viscidum Sanborn (S), growing in beef- example, synthesis of polysaccharoses and other complex peptone broth, nitrate broth, and, in the case of the latter compounds through the action of various microorganisms on organism, beef-peptone gelatin. Pseudomonas Juorescens sugars, the formation of mucilaginous solutions, and the (Fly1gge) Migula revealed gelatinous condition prosimilar cultural properties. d u c e d in suspensions of The threads obtained by cellulose by n u m e r o u s S AS investigation (Jf the microdrgariisrns involrcci i r i this method proved to be species of fungi are among the formation of pulp and paper iiiill s h e s , the autlltjrl the reactions which have e n t i r e l y t o o fragile for has emphasized the dive.nity of the slime flora and tile p r a c t i c a l purposes, and a definite b e a r i n g u p o n heterogeneity of the vkcw materials produced. .411iong the utilization of fibrous other g r o u p s of microthe isolations oerd8in yeastlike fom., belonging to the organisms were included cellulose. genera Oidium and -Wonilia, oaatrred prominentty. Thece The slimes formed by in t h e investigation. organisms develop with great rapidity k carbhydrate-rich Oidium and Monilia are Those concerned in the media, producing doughy and somewhat rubbery y o s t l l s . complex m i x t u r e s , the f o r m a t i o n of p u l p and lEither potato decoction or &met of groundwood, with the precise chemical identity paper mill slimes yielded addition of glycerol, dextrin, or gluco~e,may be employed. of which has not yet been the m o s t f a v o r a b l e reThe production of aatkfactory parcthmentlike tneriilirilnes fully determined. They sults. from these dime g r o w t h hrs been achieved by con~niiriution e v i d e n t l y consist of a of the material in water, deposition of the slime Itnrticles m u c i l a g i n o u s fraction upon the ht-formingl suubetrrrtum ir?th the aid 04 uti sspiraPULPAND PAPER MILL soluble in acidified methator, and lubaiarrfion of the readtine; membrane by means of SLIMESAND THEIR nol; , constituents resenia glycerok& mineral 02 treatment. The particles PROPERTIES bling the so-called oxycelcoalesce to form a continuous, uniform, semi-transparent Reference has already lulose and hydrocellulose membrane. The final prows was completed by drying in groups; and a portion inbeen made to the various FICCRE 1. II.LCSTHTIOS OF SEYI-.IH~SSPAHE~,~ ~IE.\IUHASE soluble in 17.5 per cent groups of microorganisms sodium hydroxide, which i s o l a t e d by the author may be closely related to during the investiaation ofthese slimes (4): The isolations represent types which cellulose itself. This material gelatinizes in alkali and assumes predominate under the varied environmental conditions exist- a yellow color, particularly the portion which goes into solution. ing at mills in different localities. A list follows of the genera I n concentrated hydrochloric acid certain parts of the slime mass gradually take on a pinkish violet color. Upon applicato which some of these microorganisms belong: tion of heat, the entire mixture turns brown and slowly disFILAMENTOUS YEAST-LIKE FUXGIOF THE BACTERIA BACTERIA FUNQI MOLD TYPE solves with continued boiling. A brownish black deposit, probAchromobacter Actinomgces Oidium Aspergillus ably carbonaceous matter, is formed following this treatment. Pseudomonas Spirophyllum Monilia Penicillium Escherichia Cladosporium On hydrolysis, the slime yields reducing sugars. The product Aerobacter Chaetomium becomes viscid and slowly dissolves, with moderate heating, Bacillus Acrostalagmus Trichoderma in zinc chloride solution. Following a brief treatment with Alternaria Mucor this reagent, the gelatinized slime can be regenerated in water These groups, which are by no means complete, include in the form of strands. Microchemical tests, using iodine numerous forms whose activities extend to pulp discoloration reagents, reveal a mixed composition. The slimes stain partly and deterioration. Other authors have emphasized the slime- yellow to yellowish brown and partly reddish brown, with forming activities of the alga-like iron bacteria (1). The blue particles distributed over the field. The blue areas bemajority of the forms cited above develop persistently in a come far more extensive following a short treatment in zinc groundwood system and build up extensive growth accumula- chloride solution. The slimes show the reaction with Schiff’s reagent but the tions. Groundwood pulp is eminently suited to the cultivation of microorganisms and unless, in a groundwood mill, Fehling’s test is negative. They are only slightly soluble in systematic methods of prevention are employed, excessive cuprammonium. On drying, a hard, horny, or brittle product multiplication and growth will result. I n this connection, is formed. The slime culture is highly concentrated and gives determinations of total bacterial numbers, carried on peri- up water with extreme slowness. Water may be drained off odically, are helpful in indicating the effectiveness of control only with the aid of an aspirator. Considerable quantities of slime are produced by a species measures. Slime development frequently occurs, as well, in of Oidium, evidently a slimy variety of Oidium lactis, growing sulfite, paper mill, and raw water systems. The various formations of slime are governed by a number in potato decoction or extract of groundwood containing of factors, including the growth characteristics of the pre- glycerol, dextrin, or glucose. The slime mass usually separates
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INDUSTRIAL AND ENGINEERING CHEMISTRY
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from the liquid portion of the culture, in a compact clot. Another isolated species of Oidium forms a thick ring which eventually breaks loose, the segments of "rope" remaining intact. The rest of the culture is highly viscous. This organism derelops slowly on potato-glucose agar with a restricted, raised, yellowish growth. Oidium also occurs in association with Monilia or Torula. A slimy species belonging t o the former genus and bearing a resemblance to Monilia candida also produced copious amounts of the mucilaginous mixture. An intimate association was discovered of this organism with the rope-forming Oidium referred to above. The growth consisted of elongated, rubbery, yellow bodies which, niicroscopically, revealed no features of structure that might assist in their identification. Such findings illustrate the complexity and heterogeneity of the microbiological formations which may occur under the varied environmental conditions found in pulp and paper mill\.
Uniform slime suspensions were obtained by agitation of the slime masses and the addition of a definite amount of water. Deposition of a quantity of this suspension upon a sheet-forming substratum, aided by the rapid withdrawal of water, resulted in coalescence of the slime particles and the production of a continuous, semi-transparent membrane of the type illustrated in Figure 1. I n order to give the sheet the necessary flexibility and resilience, the freshly prepared film was treated successively with glycerol solution and mineral oil, during steam-drying. ilt this stage in the process the membranes are capable of considerable stretch and may be manipulated to yield a high degree of transparency. Suitable finish can be produced by sizing or coating with resinous or waxy materials. The highly adhesive qualities of the slime particles and also of the freshly prepared film indicate their possible value as intermediary binding and cementing agents.
USEFULA P P L I C A T I OOF~ ;SLIME ~ SUSP~NSIONS Laboratory cultures were prepared in wide-mouthed, liter, Erlenmeyer flasks, each containing 200 cc. of medium. The slime growths may be gathered after short incubation intervals or allowed to increase, giving much larger yields. I n the latter case, clots weighing considerably over 100 grains were produced in 3 to 4 weeks. The moisture content of the slime clot is approximately 90 per cent.
LITERATURE CITED (1) Gesell, W. H., PaperInd., 14, 297 (1932); Schmid, W., Zellstofu. Papier, 10, 870 (1930); Pattillo, D. K., Pulp & Paper M a g . Can., 31, 551 (1931). (2) Sanborn, J. R., IND. ENG.CHEM.,25, 288 (1933); Science, 77, 290 (1933). (3) Sanborn, J. R., J . B a d , 23, 350 (1932). (4) Ibid.,26, 373 (1933). R ~ C E I V EDecember D 7, 1933.
Corrosion of Metals by Phenols F. H. RHODES,P. A. RIEDEL,AKD T-. K. HESDRICKS, Cornel1 University, Ithaca, N. Y MONG the organic compounds that are known to corrode steel and other metals are phenol and the cresols. The corrosion observed in stills and fractionating columns handling coal-tar oils is probably due, in part a t least, to the action of phenolic compounds on the metal. In the design of stills for the refining of phenol and cresols, the metal used in the construction of the condenser coils must resist the chemical action of the vapor and must not cause discoloration of the finished product. The corrosive action of tar acids on metal is also of importance in connection with the operation of the recently developed processes for the purification of petroleum oils by fractional extraction with cresol. But little information concerning the corrosion of metals by tar acids has been published. i\lIacleod, Chapman, and Wilson (1) found that cold cresylic acid attacks lead rapidly and is blackened by contact with nickel, has comparatively little action on tin or on copper, and corrodes aluminum and chrome steel only slightly. They report that hot cresylic acid acts rapidly on lead and aluminum, is darkened by nickel, and attacks copper and chrome steel only slowly. Inasmuch as they do not indicate the composition of the cresylic acid used, the areas of the test pieces of metal employed or the exact conditions under which the tests were made, their results have only qualitative significance. Seligman and Williams ( 2 ) found that aluminum is attacked rapidly by hot dry phenol or hot dry cresol, but that the pre3ence of a small amount of water inhibits the corrosion.
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Zinc, commercial galvanizing spelter Nickel malleable ( 0 2 5 % Cu, 0.066% Mn, 0.59% Fe, 0.019% S, 0.21% Si, O'.OE% C ) Monel metal (29.9S%,Cu, 66.75% Ni, 1.61% Fe) Silver, pure electrolytic sheet High-carbon steel (1.4% C ) Low-carbon steel (0.2% C) Brass (64.15% Cu 35.3% Zn) High-chromium stekl (14.3% Cr, 0.12% C, 0.004% S, 0.006% P, 0.2% Si. 0.52y0 Mn) Chromium-nickel steel (17.9%Cr, 7.6% Ni, 0.15%, C, 0.006% S, 0.005% P, 0.24% Si, 0.48% M n )
The metals used in the present experiments were as follows:
The phenol and the cresols were prepared from material purchased as chemically pure and further purified by two distillations, in glass, through an efficient fractionating column. The purified materials were stored in sealed containers until used. In determining the rates of corrosion by dry tar acids at 25' C., a weighed and measured strip of the test metal was placed in a large test tube and covered with the melted acid. The tube was then closed with a stopper carrying a calcium chloride tube to exclude moisture and was allowed to stand in a thermostat a t 25" C. At the end of the test period the metal was removed, washed and dried, and reweighed. The experiments to determine rates of corrosion at this temperature were continued for about 100 days. In measuring the corrosion by wet acids at ordinary temperatures, the same general procedure was adopted, except that about 10 per cent of water was added to the acid and the tubes were closed with loosely fitting stoppers t o exclude dust. In measuring the rates of corrosion by the vapors of the tar acids at their boiling points, the measured and weighed test strip was placed in a bulb connected between a flask in which the tar acid was being boiled and a reflux condenser in which the vapor was being condensed. The apparatus was so designed that the metal was in contact only with the vapor and with the hot condensate that naturally condensed on the surface of the metal but was not washed by the stream of condensate from the reflux condenser.
Aluminum, commercial pure aluminum sheet Cop er, electrolytically refined annealed Leaf, chemical sheet, 99.8% phre
DRY TARACIDS. The rates of corrosion of the various metals by the dry tar acids a t 25' C. mere as follows:
EXPERIMENTAL WORK
