Determination of the Paper Quality as a Substrate for Oyster Mushroom Cultivation

Pleurotus sp. is well known commercially cultivated white rot fungus. It is capable of utilizing a wide
range of agro-wastes such as Artichoke waste, Banana leaves and pseudostem, Barley straw, Brassica-haulms, Cinnamon leaves, Coffee sawdust, Corncobs, Cotton wastes, Groundnut shells, Oat straw, Rice straw, Soybean stems, Sugarcane bagasse, Wheat straw, wood waste etc. These substrates are rich in cellulose, hemicelluloses and lignin content. To utilize these substrates mycelium of Pleurotus sp. has to secrete extracellular enzymes complex that could depolymerised these polymers. This complex includes the oxidative enzymes laccase  and manganese peroxidase , which is involved in lignin degradation, and the hydrolytic enzymes xylanase and cellulase, which are involved in hemicellulose and cellulose degradation, respectively. According to our previous findings, beside plant wastes, Pleurotus sp. is capable of utilizing the substrate from animal and fungal origin. Apart from this, few industrial wastes viz., pulp and paper mill effluent, baby diapers, oxo-biodegradable plastic waste  etc. have also been utilized by this mushroom. A number of these waste have been employed as feedstock in solid state fermentation (SSF) processes using higher Basidiomycetus fungi for the production of mushroom food which offers an alternative for developing unconventional source of proteins. Among the aforesaid substrates, agro-wastes are the most extensively used substrate for small scale/commercial cultivation of edible mushrooms. The availability of these agro-wastes are limited in the big cities, therefore, people are unable to grow their own mushrooms. They depend on malls, vegetable stores etc for their mushroom requirements. Waste paper, on other hand, is an accessible cellulosic waste that provides carbon source to mushroom and promotes their cultivation in such areas. However, it is necessary to analyse the safety aspects of using these waste papers for mushroom cultivation before recommending it for consumption especially when printed paper waste is used as substrate because mushrooms are well known for their ability to bioaccumulate the toxic substances in their carpophores. A lot of work has been done on news papers either as a master substrate  or as a supplement  for oyster mushroom production. Work on other paper type is less documented. In present communication, Eight different kinds of papers, viz., glaze paper, brown paper, news paper, magazine paper, chart paper, kite paper, rough copy paper and A-4 size printing paper and two types of cardboards viz., corrugated cardboard and card board were evaluated for different manifestations of white oyster mushroom Pleurotus florida Strain-P1.

The results regarding various parameters of mushroom production are summarized in Tables 1-3 and
Figs. 1-2.
Vegetative and fruit development phase: The mushroom was utilized all the substrates for their growth and sporophore formation. The compact mass of whitish and cottony growth was formed in all the substrates due to complete impregnation of mycelium. Mycelial ramification was comparatively more condensed and vigorous in case of Magazine paper, brown paper and in both kind of cardboard over control. The glaze paper and kite paper showed poor mycelia run. Especially, in case of kite paper, not all of the waste paper area was covered by the hyphae. On the contrary, some areas were entirely devoid of the mycelium. Majority of substrates took almost equal time for spawn run primordial development and fruit bodies’ maturation. The fastest mycelia development (21 days), primordial development (25 days) and fruit body formation (31 days) were realized with brown paper while kite paper took maximum time for aforesaid manifestations (28, 34 and 40 days). 

Yield and biological efficiency of mushroom: The yield parameters such as yield and biological efficiency varied among themselves. The crop of mushroom was harvested in three flushes where yield and biological efficiency ranged between 190-495 gm, 38-99% with significant difference (P=0.05) among substrates. Magazine paper (450 gm; 90%) and card board (495 gm; 99%) produced significant (P=0.05) yield and biological efficiency over control (Table 1). They also showed highest percentage yield increase over others (Table 2). Rest of the substrates showed significant reduction in yield. The percentage contribution in yield of different substrates was also evaluated. Among the substrates, card board contributed 14 % of total mushroom production followed by magazine paper (13%) and news paper (12%) (Fig. 1). Overall, in our investigation, oyster mushroom showed healthy biological efficiency on paper and cardboard substrates.

Number and average weight of sporocarp: The average number of fruit bodies harvested varied among the substrates ranged between 23-64 sporocarps/bag. Majority of substrates showed significant reduction over control in terms of number of sporocarp produced. Only Magazine paper and cardboard produced significant number of mushroom fruit bodies of 56 and 64, respectively which were at par to each other. The average weight per sporocarp ranged 7.73-10.29 gm for different treatments. A significant reduction in mushroom weight was observed in magazine paper (8.04 gm), brown paper (8.24 gm) and chart paper (8.26) over control. The Rough copy paper (8.94 gm), glaze paper (9.83 gm), A-4 size printing paper (9.67 gm) and kite paper (9.00 gm) were statistically similar with control. Only
corrugated cardboard (10.29 gm) was found significant in terms of average weight per sporocarp.

Pleurotus sp. synthesizes extracellular enzymes during their growth on lignocellulosic materials. This enzyme complex depolymerised these polymers in to small water soluble sugars which can be processed by mushrooms. Because of papers and cardboards are biosynthetically composed of cellulose, hemicelluloses and lignin components, the Pleurotus utilized these substrates for their mycelial growth and fruit bodies formation. This finding is supported by Florian  who reported growth and development of fungal species on the objects of cultural heritage made of or supported on paper which is supported by their enzymatic action that cause biodegradation of paper. Apart from enzymes, organic acids are excreted by fungi, which cause a gradual loss of mechanical strength in paper. In addition, physical and chemical forms of cellulose, present in a paper sheet, influence the bioreceptivity of paper. The native cellulose is mainly crystalline with some amorphous sites, whereas the cellulose present in a paper sheet, by having already undergone physical and chemical processing, contains a larger number of amorphous sites along the polymer. These sites are more susceptible to biodeterioration and therefore have a higher bioreceptivity for cellulolytic microorganism. Comparatively more condensed and vigorous growth of mycelia in case of magazine paper, brown paper, and both kind of cardboards was probably due to this reason. The poor mycelia growth in glaze paper is probably due to coating of the paper which might be toxic to mushroom mycelium and therefore, inhibit the colonization and growth of the oyster mushroom mycelium while poor absorption kinetic in kite paper might be due to its light weight.

The mushrooms gave satisfactory yield and biological efficiency on every paper and cardboard substrates which also attributed to the wide range of cellulose and hemicellulose in this substrate. These values are higher than reported from many unconventional lignocellulosic plant wastes . It is in conformity of Mandeel et al.,  who reported Oyster cultivation on shredded office paper and cardboard yielded more edible sporophore biomass than other lignocellulosic residues. Earlier, Yildiz et al., found the mixture of wheat straw and waste paper (1:1 w/w) as best substrate combination for mushroom production, respectively. They also stated that the mixtures which involve waste paper generally produced higher yield values when compared to the other combinations. Girmay et al., recommended paper waste as suitable substrates for the cultivation of oyster mushroom. Amongst the paper and cardboard wastes, cardboard produced most significant yield and biological efficiency and ranked top in this investigation. This was due to the fact that cardboard is rich in celluloses and lignocelluloses and includes minor portions of starch. Earlier, Owaid et al.,  found best significant (P<0.05) yield of Pleurotus ostreatus on cardboard substrate. Philippoussis  summarized earlier work on the biological efficiency of Pleurotus ostreatus and P. pulmonarius on various substrates. The value reported from cardboard was quite higher than those of other substrate. 

The overall results in present study concluded that use of paper and cardboard is much efficient in oyster mushroom cultivation. These results are not only useful for mews houses, semi-houses and flatlet houses dwellers but also waste management faculties who wish to cultivate mushrooms and riddance of the paper and card board waste at the same time. 

 

Cite this as  Siddhant, O.P. Ukaogo, S.S. Walakulu Gamage, Ruchira Singh and Mahesh Kumar (2020). Determination of the paper quality as a substrate for oyster mushroom cultivation. In: Dr. Afroz Alam (ed.) Modern Research in Botany. Book Publisher International, West Bengal and United Kingdom.  pp. 117-125.