Di manakah kamu sedangkan jalan ini terlalu jauh, Adam telah mengharungi pelbagai penat lelah, kerananya juga Nuh kepenatan, Ibrahim khalilullah dicampak ke dalam api, Ismail di tidurkan untuk disembelih, Yusuf dijual dengan harga murah dan merengkok di dalam penjara beberapa tahun, Zakaria dibelah kepalanya dengan gergaji, Yahya disembelih, Ayyub menghadapi penyakit yang memeritkan, Isa terpaksa berjalan bersama generasi yang ganas dan Muhammad s.a.w. mengharungi pelbagai bentuk penentangan… ….sedangkan kamu membuang masa dan bermain-main. Itulah erti kehidupan, erti perhambaan dan erti tanggungjawab yang difahami oleh mereka yang menjadikan mereka sedemikian rupa

-Al-Fawaid; Ibnu Qayyim Al Jauzy

Pengamatan:

Ketahuilah bahawa (yang dikatakan) kehidupan dunia itu tidak lain hanyalah (bawaan hidup yang berupa semata-mata) permainan dan hiburan (yang melalaikan) serta perhiasan (yang mengurang), juga (bawaan hidup yang bertujuan) bermegah-megah di antara kamu (dengan kelebihan, kekuatan dan bangsa keturunan) serta berlumba-lumba membanyakkan harta benda dan anak pinak; (semuanya itu terhad waktunya) samalah seperti hujan yang (menumbuhkan tanaman yang menghijau subur) menjadikan penanamnya suka dan tertarik hati kepada kesuburannya, kemudian tanaman itu bergerak segar (ke suatu masa yang tertentu), selepas itu engkau melihatnya berupa kuning; Akhirnya ia menjadi hancur bersepai dan (hendaklah diketahui lagi, bahawa) di akhirat ada azab yang berat (di sediakan bagi golongan yang hanya mengutamakan kehidupan dunia itu) dan (ada pula) keampunan besar serta keredaan dari Allah (disediakan bagi orang-orang yang mengutamakan akhirat) dan (ingatlah, bahawa) kehidupan dunia ini tidak lain hanyalah kesenangan bagi orang-orang yang terpedaya (57:20)

Demi matahari dan sinarnya di pagi hari
Demi bulan apabila ia mengiringi
Demi siang hari bila menampakkan dirinya
Demi malam apabila ia menutupi

Demi langit beserta seluruh binaannya
Demi bumi serta yang ada di hamparannya
Demi jiwa dan seluruh penyempurnaannya

Allah, Subhanallah … Allah, Subhanallah
Allah, Subhanallah … Allah, Subahanallah

Allah mengilhamkan sukma kefasikan dan ketaqwaan
Beruntung bagi yang mensucikan-Nya
Merugi bagi yang mengotori-Nya … Subhanallah

Graviti seorang daei akan meningkat apabila dia berada dilingkungan orang-orang soleh, ataupun apabila dia berada di kalangan orang-orang yang kurang soleh – as in fasik. Saya lebih berminat untuk membincangkan perkara yang kedua – yakni hal itu menyebabkan jiwanya yang secara batinnya ingin memenangkan kebaikan bergelojak rasa ingin membanteras. Saya telah menjumpai website yang memaparkan gambar-gambar reunion sekolah saya dahulu – dan saya telah mencapai beberapa konklusi – dan bisa saya panjangkan daripada bacaan saya tentang “Tanggungjawab Pelajar Islam dalam Memulihkan Negara-negara Islam”. Antara pemerhatian saya ialah:

1- Walaupun terdiri daripada golongan professional, mereka ini lebih berkiblatkan barat daripada mengambil intipati Islam. Secara amnya, golongan professional negara ini lebih suka mengikut acuan barat, lebih-lebih lagi bagi mereka yang graduate dari luar negara. Yang graduate dari dalam negara juga sama. Tidak sah kalau tidak menjemput penyanyi/penghibur/pelawak/manusia yang terkinja-kinja di atas pentas + berpakaian tidak senonoh bagi “menghiburkan” (kononnya) tetamu yang hadir. Sukarnya mendapatkan majlis-majlis keramaian yang membesarkan nama Allah – maksud saya majlis-majlis seperti reunion.

Tiap-tiap diri (sudah tetap) akan merasai mati, kemudian kamu akan dikembalikan kepada Kami (untuk menerima balasan) (Al-Ankabut:57)

2 – Dan jika engkau menurut kebanyakan orang yang ada di muka bumi, nescaya mereka akan menyesatkanmu dari jalan Allah; tiadalah yang mereka turut melainkan sangkaan semata-mata dan mereka tidak lain hanyalah berdusta (Al-An’am:116) Jika kita berpakaian seperti mereka (yakni the kuffar) samalah kita seperti mereka – ini adalah contoh paling mudah. Belum termasuk cara berfikir, hidup, cara kita bergembira dan lain-lain

Muslim yang ingin mempersiapkan diri dalam perjuangan Islam perlu memperbaiki dirinya agar sentiasa terkehadapan dari manusia lain. Risalah Islam yang syumul ini hendaklah difahami dengan membentuk diri yang syumul juga. Maka hendaklah diteliti di sini tentang aspek-aspek seorang daie Muslim dalam rangkanya untuk menjadi seorang Muslim yang sempurna.

Sifat-sifat yang perlu ada pada diri duah ialah:

Kuat tubuh badan (Qawiyyal Jism)

Dakwah berat tanggungjawab dan tugas – perlukan badan yang sihat dan kuat.

Rasulullah saw menitikberatkan soal ini. Maksud Hadis : Mukmin yang kuat itu lebih baik dan lebih dikasihi Allah dari mukmin yang lemah, tetapi pada keduanya ada kebaikan.

Pesanan al-Banna:

Memeriksa kesihatan diri,mengamalkan riyadhah dan tidak memakan/minum suatu yang merosakkan badan.

Akhlak yang mantap (Matinul Khuluq)

Akhlak kita ialah Al-Quran dan ditunjukkan oleh Nabi saw.

Dijelaskan beberapa unsur oleh Imam Al-Banna dalam kewajipan dai iaitu sensitif, tawadhu, benar dalam perkataan dan perbuatan, tegas, menunai janji, berani, serius, menjauhi teman buruk dll.

Fikiran yang berpengetahuan (Mutsaqqafal Fikri)

Perlu berpengetahuan tentang Islam dan maklumat am supaya mampu menceritakan kepada orang lain.

Perlu bersumberkan kepada Al-Quran dan Hadis dan diterangkan oleh ulama yang thiqah.

Pesan Imam Banna: Perlu boleh membaca dengan baik, mempunyai perpustakaan sendiri dan cuba menjadi pakar dalam bidang yang diceburi.

Mampu membaca Al-Quran dengan baik, tadabbur, mempelajari seerah, kesah salaf dan kaedah serta rahsia hukum yang penting.

Mampu berusaha (Qadiran ala Kasbi)

Walaupun kaya, perlu bekerja.

Tidak terlalu mengejar jawatan dalam kerajaan/resmi.

Meletakkan jawatan dan tempat kerja mengikut keperluan dakwah lebih utama dari gaji dan pendapatan.

Melakukan setiap kerja dengan betul dan sebaiknya (ihsan).

Menjauhi riba dalam semua lapangan.

Menyimpan untuk waktu kesempitan.

Menjauhi segala bentuk kemewahan apatahlagi pembaziran.

Memastikan setiap sen yang dibelanja tidak jatuh ke tangan bukan Islam.

Akidah yang sejahtera (Salimul Aqidah)

Redha Allah sebagai tuhan, Islam sebagai Agama dan Muhammad saw sebagai Nabi.

Sentiasa muraqabah Allah dan mengingati akhirat, memperbanyakkan nawafil dan zikir.

Menjaga kebersihan hati, bertaubat, istighfar, menjauhi dosa dan syubhat.

Ibadah yang betul (Sahihul Ibadah)

Perlu melakukan ibadat yang meninggikan roh dan jiwanya.

Perlu belajar untuk membetulkan amalannya dan mengetahui halal dan haram.

Tidak melampau atau berkurang (pertengahan).

Mampu melawan nafsu (Mujahadah ala Nafsi)

Perlu azam yang kuat untuk melawan kehendak nafsunya dan mengikut kehendak Islam.

Tidak menghiraukan apa orang kata dalam mempraktikkan Islam.

Dai mungkin melalui suasana sukar yang tidak akan dapat dihadapi oleh orang yang tidak biasa dengan kesusahan.

Menjaga waktu (Haarithun ala Waqtihi)

Waktu lebih mahal dari emas, waktu adalah kehidupan yang tidak akan kembali semula.

Sahabat sentiasa berdoa agar diberkati waktu yang ada pada mereka.

..Aku adalah makhluk baru.. menjadi saksi kepada manusia.

Tersusun dalam urusan (Munazzamun fi syu’unihi)

Untuk manfaatkan waktu dengan baik.. perlu penyusunan dalam segala urusan.

Gunakan segala masa dan tenaga tersusun untuk manfaat Islam dan dakwah.

Berguna untuk orang lain (Nafi’un li ghairihi)

Dai umpama lilin yang membakar diri untuk menyuluh orang lain. Dai adalah penggerak dakwah dan Islam. Masa depan Islam, hidup mati Islam bergantung kepada dai.

Amal Islam ialah untuk menyelamatkan orang lain dari kesesatan.

Dai merasa gembira bila dapat membantu orang lain. Paling indah dalam hidupnya ialah bila dapat mengajak seorang manusia ke jalan Allah.

Tanah Kubur, Part 1, sila ke YouTube.com untuk part-part yang seterusnya. Jzkk.

A review on efficacy of genus Pseudomonas in hydrocarbons degradation

N. H. SHAHIDAN

School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia

Abstract

Pseudomonas is well-known as an effective hydrocarbon degrader. This potential of Pseudomonas species has led to several strains being genetically engineered to assist in cleaning up contaminated site. The efficacy of Pseudomonas mechanism in hydrocarbon biodegradation is largely depending on its ability to form biosurfactant called rhamnolipid. Surface active molecule rhamnolipid acts as a booster in increasing the rate of hydrocarbon consumption. However, environmental factors such as pH, temperature and salinity have significant effects on rhamnolipid action. Since Pseudomonas can also produce extracellular enzymes such as lipase, its potential as a hydrocarbon degrader surpasses other bacterial genera such as Micrococcus, Aeromonas and Serratia.

1) Introduction

Being ubiquitously found in soil and marine environment, genus Pseudomonas has been classified as one of the most effective oil degraders (Hong et al, 2005), along with other bacterial genera such as Micrococcus, Bacillus, Aeromonas, Serratia and Proteus (Benka-Coker & Ekundayo, 1996; Rahman et al, 2003). The most widely studied Pseudomonas aeruginosa has a good reputation as the most powerful oil degrader among Pseudomonas species. Tang et al (2006) reported P. aeruginosa has the capability to consume on long-chain length alkenes and able to survive for at least five years at oil contaminated site, without facing detrimental effects on its morphology and size. As universal oil degrader, some strains of Pseudomonas have been used commercially to alleviate contaminated sites that have hydrocarbons as main pollutants through bioremediation technologies (Evans et al, 2004). Hydrocarbon products contain an intricate mixture of different components, both aromatic and aliphatic hydrocarbons. Kerosene for instance, consist components ranging from C8 to C18 n-alkenes, as well as aromatic groups. In contrast, gasoline has aromatic groups such as toluene, dimethylbenzene and trimethylbenzene as major components, whilst having alicyclic hydrocarbons in small amount (Wongsa et al, 2004). A study conducted by Wongsa et al (2004) once again discovered P. aeruginosa was the best kerosene degrader. On the other hand, based on study done by Barathi and Vasudevan (2001), P. fluorescens was shown to effectively utilize hexadecane, hexane, decane, kerosene and crude oil.

Extraordinary mechanisms of biodegradation carried out by Pseudomonas lead to its effectiveness in utilizing hydrocarbon as energy source. This review will highlight the efficacy of Pseudomonas by exploring its degradation mechanisms in general context; particularly on the production of rhamnolipid and secretion of extra cellular enzymes, mainly lipase.

2) The production of rhamnolipid by Pseudomonas

Rhamnolipid, a biosurfactant synthesized by some Pseudomonas strains has been proven to be essential in assisting the degradation of hydrocarbons, especially alkenes (Tang et al, 2006). By definition, biosurfactant is a “group of surface active molecules” that is naturally produced by microorganisms to enhance biodegradability of hydrocarbon-based-substrates (Tang et al, 2006; Illori et al, 2005). Barathi and Vasudevan (2001) mentioned that biosurfactant is not just potentially limited to breaking down aliphatic hydrocarbons such as alkenes, but also recalcitrant polyaromatic compounds such as naphthalene and phenanthrene.

Inakollu et al (2004) stated that a number of strains of Pseudomonas characteristically capable of producing biosurfactants. Other than P. aeruginosa, P. fluorescens can also form biosurfactant before the degradation of oil occurs (Evans et al, 2004; Barathi & Vasudevan, 2001). The availability of biosurfactant increases the surface area-in-contact for bacterial enzymatic activities (Wongsa et al, 2004). Inakollu et al (2004) added by minimizing the surface tension and droplet size, biosurfactants stimulate the degradation in natural way. Other organisms such as Torulopsis bombicola and Mycobacterium spp. also form biosurfactant (Ilori et al, 2005). The degradation of crude oil, pyrene and phenanthiene for instance are speed up effectively due to the presence of rhamnolipids manufactured by P. aeruginosa (Tang et al, 2006; Inakollu et al, 2004; Cybulski et al, 2003). Tang et al (2006) also mentioned that the buildup of rhamnolipids might have a major impact on the enhancement of crude oil degradation; this is strongly supported by relative correlation between emulsification time and initial amount of rhamnolipids secreted by P. aeruginosa ZJU.

3) Factors affecting the effectiveness of rhamnolipid actions

3.1 Gene regulation

The mechanism of gene regulation enables production of rhamnolipid to be controlled. Ochsner et al (1994) stated that rhlR gene is essential in synthesizing rhamnolipids since the interruption at this locus had contributed to the formation of “rhamnolipid-deficient mutant strains”. Tang et al (2006) also agreed the production of rhamnolipid is controlled by gene expression, since there is no significant relationship between amount of biomass generated and rhamnolipids production. rhlR gene that controls the productivity of rhamnolipids might be highly expressed due to environmental stress impact on quorum sensing (Tang et al, 2006).

3.2 Structure of rhamnolipid

The structure of rhamnolipid is one of the possible factors contributing to the successful hydrocarbon degradation by Pseudomonas. Different bacterial species and unique structure of an emulsifier are two variables affecting the efficacy of hydrocarbon utilization (Cybulski et al, 2003). Cybulski et al (2003) highlighted there is a strong correlation between the structure of emulsifier and rate of hydrocarbons biodegradation, even among Pseudomonas strains. P. aeruginosa strain, for example is shown to conduct emulsification better than P. putida.

Figure 1. Chemical structures of rhamnolipid (Adapted from Urum et al., 2006)

The significance of rhamnolipid structure in assisting the degradation is not fully understood. However, it can be concluded that the structure of surfactant does affect the magnitude of hydrocarbon degradation as different surfactant with different structure have different effectiveness level (Cybulski et al, 2003).

3.3 Environmental factors

Environmental factors play a crucial role in influencing the productivity and efficacy of rhamnolipids. In general, as a biosurfactant, rhamnolipid activity is controlled by environmental conditions such as pH, salinity and temperature (Ilori et al, 2005; Inakollu et al, 2004; Jirasripongpun, 2002). Ilori et al (2005) pointed out that the chemical structure of biosurfactant gives an apparent benefit for hydrocarbon degradation and very unlikely to be disrupted due to extreme temperature and pH. This applies to rhamnolipid as well (Figure 1). In addition, as biosurfactant is synthesized naturally by microorganisms, the production of toxic is minimized. Benka-Coker and Ekundayo (1996) highlighted the amount of oil might affect the biodegradation rate as well, corresponding to poor aeration due to the lack of oxygen. Plus, while the action of Pseudomonas in degrading oil is accelerated through the formation of rhamnolipid, size and structure of hydrocarbon substrates may conversely slow down the breaking down processes. However, the ability of Pseudomonas to secrete lipase enzyme will overcome this difficulty.

4) Comparison of the effectiveness in rhamnolipid action to other biosurfactants

Noordman and Janssen (2002) claimed the degradation of hydrocarbon, hexadecane by rhamnolipid has higher rate compared to other biosurfactants. Direct contact between bacterial cells and hydrocarbon droplets is almost certainly due to the minimization of hydrophobicity of cell surface “after the extraction of lipopolisaccharide from the cellular envelope by rhamnolipid”, hence accelerate the microbial degradation of that particular hydrocarbon. Urum et al (2006) on the other hand conducted a study comparing the effectiveness of biosurfactant rhamnolipid, saponin and sodium dodecyl sulfate (SDS). He found out rhamnolipid and saponin are almost equal in degrading crude oil, whilst SDS as the most inefficient. Nevertheless, in this case rhamnolipid is still the best biosurfactant since it is produced naturally via microbial activity, while saponin need to be extracted from quillaja bark (i.e from plant source) and SDS is a synthetic surfactant.

5) Secretion of extracellular enzymes

Pseudomonas has the capability of manufacturing few types of extracellular enzymes, and one of them is lipase. Extra cellular lipase of Pseudomonas is characteristically unique amongst other lipases produced by other microorganisms, especially its ability to resist high temperature and enzymatic action in basic environment. Therefore, Pseudomonas lipase is very suitable to be used in bioremediation application to degrade esters and lipid wastes (Hasanuzzaman et al, 2004). Vasileva-Tonkova and Galabova (2002) pointed out the process of breaking down organic pollutants mainly carried out by microbial community via the secretion of hydrolytic enzymes. Hence, along with the formation of rhamnolipid, Pseudomonas has an apparent advantage compared to other bacterial genera as a hydrocarbon degrader since it can both secrete enzymes and feed on hydrocarbons. Vasileva-Tonkova and Galabova (2002) stated that not all bacterial genera have the ability to grow on hydrocarbon as energy source, and at the same time secrete hydrolytic enzyme. This kind of microorganism like Pseudomonas appears to be rare in environment. Catalytic action mechanism of Pseudomonas is varied even amongst species, contributing to dynamic cooperation amongst Pseudomonas species themselves during the process of degradation. Lipase of P. mendocina strain 3121-1 was found to be different from lipase of other P. mendocina which is capable of acting on wide range of substrates (Bendikiene et al, 2004). Since the secretion of lipase is likely to be suppressed by sugars and other intricate substrates, hydrocarbon might be more suitable for lipase break down activity (Kanwar & Goswami, 2002).

Conclusion

Two main mechanisms in hydrocarbon degradation conducted by Pseudomonas give this genus a unique ability to degrade hydrocarbon based pollutant either naturally in environment or for commercial purposes. In other words, the use of Pseudomonas either wild-type or genetically modified strains in bioremediation technologies to clean up contaminated sites is just perfect and suit the nature best.

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